Forward Defense

This report examines U.S. force posture in Europe — including the military capabilities, personnel, infrastructure, and agreements that support defense operations and plans — and makes recommendations for future U.S. posture. It finds that the United States needs a robust, long-term military force posture in Europe, focused on the North Atlantic Treaty Organization’s (NATO) eastern flank, to deter future Russian aggression.

First, the United States needs a robust, long-term military force posture in Europe, focused on the North Atlantic Treaty Organization’s (NATO) eastern flank, to deter future Russian aggression. Russia will likely remain a dangerous threat to the United States and Europe over the next several years. Russian president Vladimir Putin retains the political will and intentions to expand Russian power abroad, and Russia is reconstituting its military capabilities with help from China, Iran, and North Korea. A significant downsizing of U.S. forces in Europe could severely weaken deterrence and embolden a revanchist Russia.

Second, the United States should permanently station a U.S. Army armored brigade combat team (ABCT) in Poland to strengthen deterrence and reassure the United States’ Eastern European allies in response to a long-term Russian threat. Shifting the current rotational ABCT from Operation Atlantic Resolve to a permanent presence in Poland should be part of a 4+2 posture in Europe. This posture would include four U.S. brigade combat teams (BCTs) — three forward-stationed BCTs in Poland, Italy, and Germany, along with one rotational BCT in Romania — and two divisional headquarters, in Germany and Poland.

Third, the U.S. Army should remain a bulwark for deterrence in Europe. A war against China in the Indo-Pacific will likely center on air and naval operations. However, some ground forces — from the U.S. Marine Corps, U.S. Army, and allies and partners — will be helpful for both deterrence and warfighting, including on the Korean peninsula.

In examining U.S. posture in Europe, this study asks three main questions. What are the main security threats in Europe for the United States and its allies? What are U.S. interests in Europe? What is the appropriate U.S. force posture in Europe? In answering these questions, this study comes to several broad conclusions.

Enduring U.S. Interests in Europe

The United States has several enduring interests in Europe. They include protecting the U.S. homeland and the security of the American people from threats based in Europe, including from Russia; promoting and expanding economic prosperity and opportunity; realizing and defending the democratic values at the heart of the American way of life; and defending and supporting the United States’ European allies. While some U.S. politicians and pundits have questioned the value of NATO, U.S. interests in Europe remain significant and enduring. Still, a number of European governments need to increase defense spending in light of the precarious security environment. Numerous NATO countries (especially those on NATO’s eastern flank) spend over 2 percent of their gross domestic product on defense, such as Poland (3.9 percent), Estonia (2.73 percent), Lithuania (2.54 percent), Finland (2.45 percent), and the United Kingdom (2.07 percent). But some others do not.

Persistent Russian Threat

Russia will likely remain a significant and dangerous threat to the United States and NATO. Russia likely does not pose an immediate conventional threat to NATO. Over the next several years, however, there are several factors that could change the military balance in Europe. The United States could become overstretched with a war against China in the Indo-Pacific, North Korea on the Korean Peninsula, or Iran or terrorist groups in the Middle East. In addition, Russia could continue to rebuild its military over the next several years with help from China, Iran, North Korea, and other countries. A Russian military victory in Ukraine — or even significant Russian military advances on the battlefield — would also increase the Russian threat.

Forward Defense Posture

The United States should take several steps to enhance its posture in Europe over the next several years in ways that are sustainable and affordable:

• Ground: The United States should adopt a 4+2 posture beginning in 2025 that consists of four U.S. BCTs — in Poland, Italy, Germany, and Romania — and two headquarters, in Germany and Poland. This force posture would involve eventually shifting from a rotational to a permanent ABCT in Poland to strengthen deterrence against a revanchist Russia.

• Air: The United States should maintain all seven forward-deployed fighter squadrons currently based in Europe and add an additional F-16 squadron to Spangdahlem Air Base.

• Maritime: The United States should continue its current naval presence in the Baltic Sea region to deter Russian aggression and strengthen interoperability with allies and partners. In addition, the U.S. Navy should supplement existing NATO anti-submarine warfare capabilities by developing and deploying additional systems to the region.

• Prepositioned Equipment and Munitions Stockpiles: The United States should bolster its prepositioned equipment and munitions stocks in Europe to enhance the readiness of U.S. forces. While the Army Prepositioned Stock 2 has been somewhat augmented by funding from the European Deterrence Initiative, the U.S. Army should take additional steps to improve the readiness of this equipment and the forces overseeing it.

• Integrated Air and Missile Defense: The United States should increase air and missile defense capabilities in Poland in coordination with a permanent ABCT. Given the utility of, and demand for, air and missile defense assets across multiple combatant commands, the Army should also prioritize the development and deployment of additional Patriot battalions.

• Nuclear Posture: The United States should increase modernization efforts, exercises, and scheduled deployments of assets to the European theater to bolster its deterrent capabilities and reassure allies. This includes modernizing its gravity bombs with the new B61-12. The U.S. military and NATO should also continue to conduct exercises with nuclear-capable platforms, including Bomber Task Force missions, to enhance readiness and assure allies of U.S. support.

• Cyber and Space: U.S. forces should continue to enhance the security and resilience of their cyber systems and networks while simultaneously assisting European partners and allies. U.S. Cyber Command (CYBERCOM) should deploy additional “hunt forward” teams to Europe to counter threats from Russia and Russian-backed groups to U.S. forces and allies.

• Security Cooperation: The United States should help strengthen European military capabilities and encourage greater investment in such areas as combat support, including short-range air defense and long-range fires; airlift; heavy maneuver forces; maritime capabilities, including sensors and survivability systems; sufficient quantities of long-range precision strike weapons; and multi-spectrum ranges to train and maintain high-readiness forces. Security cooperation efforts should also involve additional security assistance, arms sales, training, partner capacity missions, industrial base cooperation, and strategic coordination between the United States, NATO, and European states on the development of forces and capabilities. Still, a number of European governments need to increase defense spending in light of the precarious security environment.

Europe remains a vital region for the United States. The last two U.S. national security and national defense strategies prioritized China as the main global threat. But Russia’s brutal invasion of Ukraine, continuing aggression, and growing cooperation with China, Iran, and North Korea are stark reminders that the United States has significant and enduring interests in Europe as well.

CH. 01

INTRODUCTION

Russia’s February 2022 invasion of Ukraine dramatically shifted the strategic landscape in Europe, triggering the most devastating war in Europe since World War II. More Russian soldiers have died in Ukraine than in all previous Soviet and Russian wars combined since World War II, including Russia’s bloody wars in Afghanistan and Chechnya. The war has caused the most significant refugee crisis in Europe since World War II, driving over 6 million refugees to Poland, Germany, the Czech Republic, and other countries. The war also has had substantial humanitarian implications, causing widespread civilian deaths and destruction in Ukraine and disrupting public access to water, electricity, heating, health care, and education.

In addition, Russian leaders have threatened to use nuclear weapons, raising concerns about nuclear escalation. Dmitry Medvedev, deputy chairman of Russia’s Security Council and a former Russian president, remarked, “Just imagine that the [Ukrainian] offensive . . . in tandem with NATO, succeeded and end up with part of our land being taken away. Then we would have to use nuclear weapons by virtue of the stipulations of the Russian Presidential Decree.” He continued by warning that “our enemies should pray to our fighters that they do not allow the world to go up in nuclear flames.” In response, some Western leaders have worried that Russia might consider using tactical nuclear weapons if Moscow faces sustained military losses in Ukraine. “Given the potential desperation of President Putin and the Russian leadership, given the setbacks that they’ve faced so far, militarily, none of us can take lightly the threat posed by a potential resort to tactical nuclear weapons or low-yield nuclear weapons,” remarked William J. Burns, director of the Central Intelligence Agency, in April 2022.

Despite Russian aggression and an escalation in tensions between NATO and Russia, two consecutive U.S. administrations have committed to shifting military resources to the Indo-Pacific to deal with China. The Biden administration’s Global Posture Review identified the Indo-Pacific as the most important region for U.S. national security to “advance initiatives that contribute to regional stability and deter potential Chinese military aggression and threats from North Korea.” In addition, the administration’s National Defense Strategy reaffirmed that the United States’ is prioritizing the Indo-Pacific region in its efforts to counter China.

Nevertheless, there is a need to re-evaluate U.S. force posture in Europe based on Russia’s aggressive military actions and the prospect of a protracted war in Ukraine. Future U.S. posture in Europe has significant implications for deterring adversaries in Europe and other regions, including the Indo-Pacific; assuring allies and partners in Europe and other regions; fighting wars effectively if deterrence fails; and preserving security institutions, including NATO. There have been numerous studies on U.S. posture in Europe over the past several years. But the 2022 Russian invasion of Ukraine, expansion of NATO to Finland and Sweden, and Russian threats to Poland, Baltic states, and other countries create an urgent need to re-examine U.S. defense posture in Europe.

RESEARCH DESIGN

In light of these challenges, this report asks several questions. First, what are the main security threats in Europe for the United States and its allies? Second, what are U.S. interests in Europe? Third, what is the appropriate U.S. force posture in Europe?

To answer these research questions, the report pursues a mixed methods approach. To answer the first question, it assesses the conventional and nuclear balance in Europe in such areas as land, air, maritime, and nuclear capabilities. It also examines Russia’s attempts to reconstitute its military, the nature of the Russian threat to the West over the next several years, and European capabilities and capability gaps. To answer the second question, the report outlines U.S. interests and objectives in the context of broader U.S. strategic considerations. To answer the third question, the report assesses U.S. posture in several domains: land (including forward-stationed forces, rotational forces, and Army Prepositioned Stocks); air (including sensors, fighter aircraft, integrated air and missile defense, and long-range strike); naval (including all-domain naval operations, theater security cooperation, prepositioning, and the deployment of carrier strike groups, amphibious ready groups and Marine expeditionary units, and the U.S. Sixth and Second Fleets); space (including coordination with U.S. Space Command); cyber (including coordination with Joint Force Headquarters–Cyber and U.S. Cyber Command); and nuclear (including nuclear forces and dual-capable aircraft).

The project team leveraged primary- and secondary-source documents from relevant organizations (such as NATO, U.S. European Command, the Joint Staff, the Office of the Secretary of Defense, the military services, the U.S. Department of State, European countries, and EU officials), open-source materials from policymakers and subject-matter experts, and interviews.

DEFINITIONS

As used here, force posture refers to the military capabilities, personnel, footprint (including bases, facilities, and support infrastructure), and agreements that support defense operations and plans. U.S. posture in Europe is significantly influenced by agreements with host countries, which provide access to facilities, airspace, and territory. In addition, the number of U.S. military personnel in Europe is based on the deployment of U.S. forces into and out of the region, which increase as assets such as carrier strike groups or Bomber Task Force units flow into Europe and decrease as they depart. While this report focuses on U.S. posture in Europe, the United States’ regional posture is impacted by its global posture. The report adopts a broad definition of Europe in line with the area that is currently in the U.S. European Command area of responsibility, which includes 51 countries in Europe and portions of Asia and the Middle East, with a total population of nearly 1 billion people.

Overseas force posture generally involves trade-offs. On the one hand, overseas posture can help a country prepare for military operations, deter adversaries, assure allies and partners, and build local capacity through security cooperation. On the other hand, it can also incur risks by increasing the vulnerability of forces to attack from hostile states, stressing the readiness of the force, encouraging free riding by allies and partners, and potentially dragging forces into unwanted wars.

The report examines the viability of strategic and operational concepts, including dynamic force employment and agile combat employment. Dynamic force employment involves deploying U.S. forces in ways that are strategically predictable for allies and operationally unpredictable for competitors. Examples might include deploying fifth-generation fighters, Bomber Task Force missions, U.S. Army or Marine forces, or guided-missile destroyers to various locations in Europe for snap exercises with allies and partners. Agile combat employment involves the use of small, dispersed air bases abroad — rather than relying on large overseas bases — to reduce vulnerability to adversary attacks.

CAVEATS

There are several caveats about what this analysis does — and does not — attempt to do. First, the report does not conduct a systematic cost analysis of U.S. force posture in Europe, though it does broadly discuss the cost implications associated with overseas posture. This report does not build a model that includes the cost of the current condition of overseas and U.S. installations (including a need to modernize installations or restore facilities and capabilities), host-nation support that the U.S. Department of Defense receives when it stations forces in a foreign country, or the incremental costs beyond the United States’ stationing and maintaining overseas bases and forces (including the cost difference in permanent and rotational presence options).

Instead, this report focuses predominantly on strategic and operational U.S. interests, objectives, and force postures in Europe. A detailed cost analysis is important and should be a component of any final U.S. decision on force posture in the Middle East and elsewhere around the globe. But the most important determinants of U.S. force posture in the region are likely to be the relative benefits and risks of U.S. strategic objectives and interests. Additionally, the cost differential in the event of a reduction in U.S. presence in the region would be relatively minor if those forces were deployed elsewhere overseas or returned to the United States. Significant savings would only be generated if the units and force structure elements were deactivated.

Second, the report does not conduct a systematic analysis of U.S. force posture around the globe. The focus is squarely on Europe. Nevertheless, as highlighted in every chapter of this report, the analysis and conclusions were informed by U.S. global posture considerations. Any decision regarding U.S. force posture in Europe needs to be understood in the context of U.S. national security interests and U.S. posture in other regions — especially the Indo-Pacific.

Third, the report focuses on U.S. military posture in the region. It does not conduct a systematic analysis of all U.S. activity in Europe, including diplomatic activity conducted by the U.S. State Department; intelligence activity conducted by the Central Intelligence Agency, National Security Agency, and other organizations within the U.S. intelligence community; development activity by the U.S. Agency for International Development and non-governmental organizations; and financial, law enforcement, and other activity conducted by such organizations as the U.S. Department of the Treasury, Federal Bureau of Investigation, U.S. Department of Commerce, and U.S. Department of Homeland Security. These non-military actions are critical, and military force should not be viewed as the principal tool to deal with the region’s challenges.

While the report focuses predominantly on U.S. military posture, it does highlight other U.S. government actions where appropriate and acknowledges the importance of diplomacy, development, information operations, and other activities. The report does not conduct a systematic analysis of all NATO or EU militaries, though it does nest the analysis in a broader understanding of European military capabilities and political will.

ORGANIZATION OF THE REPORT

The rest of this report is divided into several parts and chapters. Part I explores the strategic landscape in Europe. Chapter 2 examines the U.S. military presence in Europe from World War II to today. Chapter 3 analyzes the evolving threat landscape in Europe, including the threat from Russia. Chapter 4 assesses European military capabilities, including at the high-end of the military spectrum. Part II turns to force posture. Chapter 5 provides an overview of U.S. interests in Europe in the context of other U.S. interests at home and abroad, as well as U.S. defense objectives. Chapter 6 offers recommendations for future U.S. force posture in Europe. Chapter 7 assesses alternative options and weighs their pros and cons. Finally, Part III provides a conclusion, with Chapter 9 summarizing the main recommendations.

STRATEGIC LANDSCAPE

CH. 02

HISTORICAL TRENDS

The United States’ military posture in Europe has considerably evolved from the end of World War II to the present. Changes to the number and types of capabilities of U.S. forces in Europe have been driven by several factors, such as the perception of threat posed by the Soviet Union and Russia to the United States and its European allies, the relative balance of military capabilities between NATO and the Warsaw Pact, the evolution of U.S. strategy and political considerations, and the relationship between the United States and its allies.

President Dwight D. Eisenhower’s “New Look” policy emphasized a reliance on nuclear weapons, though he was committed to keeping U.S. forces in Europe “as long as the need existed.” The Kennedy and Johnson administrations shifted to a policy of “Flexible Response,” which was adopted by NATO in 1967 and gave the U.S. president the ability to select from a suite of military and non-military options when responding to a crisis. The Nixon, Ford, and Carter administrations largely pursued a policy of detente with the Soviet Union before the Carter administration’s Dual-Track strategy and President Ronald Reagan’s defense buildup. The collapse of the Soviet Union and end of the Cold War led to a major drawdown of U.S. forces in Europe as the United States prioritized contingencies elsewhere. However, Russian aggression in Ukraine, beginning in 2014 and continuing through the February 2022 invasion, prompted a rethinking of the role and capabilities of U.S. forces in Europe.

This chapter provides a qualitative and quantitative assessment of U.S. military posture in Europe in the post-World War II era to the present. It examines trends in capabilities and personnel, and it identifies strategic and operational inflection points in U.S. force posture. The chapter concludes by presenting a baseline of current U.S. posture and discussing NATO force posture development. The baseline serves to inform the posture options presented in subsequent chapters.

TRENDS IN U.S. MILITARY PERSONNEL IN EUROPE

The number of U.S. military personnel in Europe shifted considerably during the Cold War, as shown in Figure 2.1. End strength in Europe peaked in 1957 at 473,000, a significant increase from the 122,000 stationed there in 1950. That figure fell by 45 percent to 262,000 by 1970 during détente. By 1985, however, the number of U.S. military personnel in Europe grew to 359,000 during the Reagan buildup. Following the end of the Cold War, the number of U.S. personnel declined nearly 42 percent by 1992 from 1985 levels, and U.S. forces continued to decrease to a post-World War II low of 66,000 in 2013. Russia’s invasion of Ukraine in 2022 led to yet another shift, with the number of U.S. forces increasing to over 100,000 by 2023.

More U.S. personnel have been stationed in Europe than any other region during periods of peace. Figure 2.2 compares the deployment of U.S. active-duty military personnel globally. U.S. forces in Asia exceeded those in Europe during the wars in Korea and Vietnam. Despite the drawdown of personnel following the Cold War, more forces remained in Europe than any other region until the wars in Afghanistan and Iraq.

The following sections detail the policy and strategic developments which shaped these trends in U.S. military and capabilities in Europe.

HISTORICAL TRENDS IN U.S. FORCE POSTURE

The End of World War II and Early Stages of the Cold War

Tensions quickly mounted between the Western allies and the Soviet Union despite collaboration between the United States, United Kingdom, and Soviet Union during World War II to defeat the Axis powers. Winston Churchill, following his 1945 electoral defeat, described this emerging incompatibility between allied and Soviet worldviews and interests the following year as the descent of an “iron curtain” over the continent, dividing East from West.

▲ Figure 2.1: U.S. Active-Duty Military Personnel in Europe. Source: Compiled by authors from various sources.

▲ Figure 2.2: U.S. Active-Duty Military Personnel Overseas, 1950–2023. Source: Compiled by authors from various sources.

Despite these geopolitical warnings, post-World War II peacetime demobilization and drawdowns of forces by Western powers proceeded at a blistering pace. U.S. end strength fell from over 12 million personnel in 1945 to just 1.4 million by 1948. The United States’ military posture in Europe reduced given its transition from an invasion force to an occupation force in Germany. In the late 1940s, the U.S. presence was roughly 150,000. By 1950, the Army’s European Command only controlled one infantry division in Germany, while four were stationed in Japan. By the time of the creation of NATO in 1949, the United States, United Kingdom, and France could barely account for 12 total divisions, which were dedicated primarily to the occupation of Germany. These forces paled in comparison to the 26 Soviet divisions forward deployed in Eastern Europe and the estimated 75 Soviet divisions based in western Russia. On balance, neither the military dimensions nor the military requirements of the emerging competition with the Soviet Union were fully appreciated by Western powers in the early stages of the Cold War.

The June 1950 invasion of South Korea by North Korea fundamentally altered U.S. and Western strategic calculus regarding the roles, missions, and necessity of military forces in confronting an expansionist and aggressive Soviet Union. Communist China and the Soviet Union backed North Korea, and U.S. leaders viewed the conflict as an attempt to impose communist rule by force on non-communist nations. The Truman administration adopted a policy of containment, as outlined in NSC-68, to limit the spread of communist and Soviet influence globally. This strategy required a buildup of both conventional and nuclear forces to meet the expansive demands of deterring and defending against Soviet aggression.

The Korean War had the practical effect of waking the United States and Europe up to the military dimensions of the Cold War. Not only did allies contribute troops and capabilities toward the defense of South Korea, but they also began prioritizing the defense of Western Europe against possible Soviet incursions. Following the outbreak of the war, the United States and NATO took steps to significantly increase their military presence. NATO plans in 1950 called for 18 active and 16 reserve divisions. The United States increased its posture in Europe to four divisions and prepositioned equipment and supplies on the continent. In a February 1952 meeting of the North Atlantic Council in Lisbon, NATO pursued an even more ambitious target of reaching 50 active and 46 reserve divisions by 1954. However, NATO failed to meet the Lisbon Force goals, only fielding 25 active and 25 reserve divisions by 1955. During this period, the U.S. military pushed for the creation of an integrated NATO command structure and took on critical NATO staff roles, including a U.S. general as the supreme allied commander, Europe (SACEUR). The United States also established U.S. European Command (EUCOM) in August 1952.

New Look and Flexible Response

In 1952, Dwight D. Eisenhower, former U.S. Army chief of staff and the first SACEUR, was elected president on a platform of balancing the federal budget. Eisenhower vowed to reduce defense spending, which had spiked under Truman, and to pursue a more sustainable defense strategy. Despite the buildup of U.S. and NATO forces, the West still faced a significant numerical disadvantage against the Soviet Union in Europe. This disparity shaped the development of the Eisenhower administration’s “New Look” strategy of massive retaliation beginning in 1953 and its eventual adoption by NATO in 1957. The policy of massive retaliation emerged out of a strategy review known as Project Solarium, which affirmed the goals of the containment strategy identified by the Truman administration. However, the strategy document which eventually emerged, NSC 162/2, outlined a more economically sustainable deterrent based on a retaliatory nuclear response. This approach reduced the role of conventional Western forces in Europe to a “tripwire” and “delaying force” that would prevent Europe from “being entirely overrun before the effect of the U.S. nuclear attack on the Soviet homeland was fully felt.”

The United States and NATO shifted their strategy from massive retaliation to “flexible response” during the 1960s and 1970s. This shift was due in part to the belief that massive retaliation was no longer a credible deterrent given expanding Soviet nuclear capabilities and the Kennedy administration’s pursuit of a more “balanced” approach to defense. The United States expanded its ground forces from 11 to 16 active divisions and deployed an additional two to Germany following the 1961 Berlin Wall crisis. Additionally, U.S. army divisions placed greater emphasis on conventional firepower, tactical mobility, and decentralized command and control. While U.S. officials felt a greater sense of optimism regarding the balance of allied conventional military capabilities against the Soviets, particularly given the United States’ qualitative advantage in terms of capabilities, U.S. forces in Europe in the late 1960s declined largely because of the U.S. war in Vietnam. During the 1970s, the U.S. military placed greater emphasis on its ability to provide outside reinforcements to NATO in the event of a crisis, including plans to deploy 10 divisions and 60 tactical fighter squadrons to Europe in only 10 days. This led to a greater emphasis on the prepositioning of Army and Air Force equipment in Europe and securing allied host-nation support.

The Dual-Track Strategy and Peace through Strength

In 1976, the Soviet Union began deploying its SS-20 intermediate-range missiles, prompting concerns from Western European allies. In response, the Carter administration and NATO announced the dual-track decision in December 1979, which entailed deploying 108 Pershing 2 ballistic missiles and 464 ground-launched cruise missiles in the United Kingdom, West Germany, and Italy. In addition, the dual-track decision involved simultaneously pursuing arms control negotiations with the Soviet Union to reduce each side’s missiles.

Under the Reagan administration, U.S. forces in Europe increased as part of a broader defense buildup. The administration’s decision to confront the Soviet Union through its “peace through strength” plan led to a buildup of U.S. military forces in Europe — in addition to the planned deployment of Pershing 2 nuclear missiles to West Germany in 1983 and NATO’s Able Archer 83 exercises in the same year. At the same time, Reagan officials also conducted a series of arms control negotiations, such as the Intermediate Range Nuclear Forces (INF) treaty, Strategic Arms Limitation Talks (SALT), and Conventional Forces in Europe Treaty.

By the end of the Cold War, a sophisticated network of political-military arrangements designed to communicate the capability and credibility of allied forces to deter a Soviet attack underpinned U.S. and NATO posture. Division-level exercises, such as REFORGER, allowed the United States to test its ability to deploy its troops from the continental United States to Europe and reseize NATO territory. NATO’s International Military Staff worked to build common war plans and interoperability standards among allies in order to minimize tactical frictions commonly associated with fighting in military coalitions. The SACEUR possessed pre-delegated authorities to retaliate against a Soviet incursion with nuclear weapons in the event that London, for example, could not be contacted during a crisis.

Post-Cold War

The fall of the Soviet Union and end of the Cold War led successive governments on both sides of the Atlantic to realize the gains of a “peace dividend” and reduce military spending, military forces, and the U.S. military presence in Europe. Building on planning that was initially conducted during the Reagan administration, Chairman of the Joint Chiefs of Staff Colin Powell developed the “Base Force” plan in 1991 to determine the future force structure requirements for the United States in the post-Cold War era. The central premise of the Base Force was that global conflict was increasingly unlikely, while regional conflicts were becoming more likely. U.S. policymakers designed the initial assumptions for the Base Force before the collapse of the Soviet Union and Warsaw Pact, but the Bush administration argued that military design and end-strength determinations were still relevant. As one observer wrote:

Like its predecessors, JSCP FY 1989-90 [which informed the Base Force], written in the spring of 1988, considered the possibility of a U.S.-Soviet confrontation that could erupt into global war as the most serious threat to U.S. interests. But, with the Soviet Union reducing its military presence in Eastern Europe, reducing and consolidating its military forces, and undertaking domestic reform, the JSCP argued that calculated Soviet aggression in Central Europe was unlikely. The more likely threats were indigenously caused conventional regional conflicts with little likelihood of direct Soviet intervention.

Accordingly, senior U.S. Department of Defense (DOD) officials argued at the time that the collapse of the Warsaw Pact meant that further reductions in nuclear forces might be warranted and that U.S. posture in Europe should also decrease. Yet they did so with a caveat: U.S. presence in Europe should not be reduced any further than the planned end strength of 150,000 personnel. The United States also returned a number of installations to host countries.

This decrease in U.S. force posture accelerated under the Clinton administration, which planned for a final end strength of 100,000 by 1996 (down from 185,000 in 1993). Yet U.S. posture in Europe only reached a low of 113,000 in 1997 because of U.S. involvement in the Balkan wars. Between December 1995 and January 1996, the United States deployed 20,000 military personnel to Bosnia under a NATO-led force to implement a peace agreement.

In 2004, the George W. Bush administration announced that it would withdraw 40,000 U.S. military personnel from Europe as part of a broader effort to redeploy and return troops to the United States. This removal included the heavy armored brigades of the 1st Armored Division and 1st Infantry Division, which returned to the United States. The reassignment of U.S. forces continued until late 2007 when Secretary of Defense Robert Gates temporarily halted the withdrawal of the last two heavy brigades. He was concerned that there was insufficient basing for the troops in the United States. U.S. military commanders in Europe also argued that armored capabilities were necessary to meet theater security requirements. Still, the number of U.S. military personnel fell by over 40 percent, from 115,000 personnel in 2004 to 66,000 in 2008. By 2011, only four brigade combat teams (BCTs) remained in Europe.

In 2012, however, the Obama administration announced that it would withdraw the two remaining armored brigades, in line with its Defense Strategic Guidance, leaving only two light BCTs. The number of U.S. personnel in Europe reached a post-World War II low of 63,000 in 2013. A rotational battalion-sized task force known as the European Rotational Force replaced the armored brigades.

As U.S. troop strength in Europe decreased and U.S. strategic priorities shifted to other regions, there were two major arguments for retaining a presence in Europe. First, some argued that the United States needed a military presence in Italy and Germany to launch and support counterterrorism operations in the Middle East, South Asia, and Africa. Second, some argued that the United States needed to maintain a robust suite of security cooperation activities to ensure that former Warsaw Pact countries continued reforming their militaries to be compatible with their recently established democratic institutions. In addition, the United States continued to deploy forces to the Balkans as part of the Kosovo Force.

Russia’s 2014 Military Action in Ukraine

Following Russia’s invasion of Ukraine in 2014, the Obama administration responded by bolstering the United States’ defense posture in Europe. In April, EUCOM launched Operation Atlantic Resolve to increase U.S. presence in the region. The operation was funded by the European Reassurance Initiative, later renamed the European Deterrence Initiative, a special account requested by the administration to fund rotational deployments, exercises, training, and security cooperation efforts with partners and allies. Much of the initial years of this funding went toward recapitalizing basing and infrastructure that had been underinvested in over prior decades. While the initial rotational deployments of the European Rotational Force in 2014 sent only a battalion-sized force to the region, those deployments expanded to meet the new mission requirements of Atlantic Resolve beginning in 2015. In January 2017, the DOD announced the beginning of a continuous armored brigade combat team (ABCT) rotational presence in Europe and back-to-back rotations of U.S. troops and equipment to Europe. By 2023, the 7,000-person rotational force included four elements: a division headquarters located in Poznan, Poland; a combat aviation brigade; an ABCT; and a sustainment task force.

In July 2020, the Trump administration announced that it planned to withdraw almost 12,000 U.S. personnel from Germany. As part of that redeployment, approximately 6,400 troops would return to the United States, while the remainder would be moved to Belgium and Italy. The Biden administration announced that the withdrawal plans were on hold shortly after taking office.

THE U.S. RESPONSE TO RUSSIA’S 2022 INVASION AND U.S. POSTURE TODAY

As Russian forces massed on its border with Ukraine in late 2021 and early 2022, the Biden administration announced several deployments as part of its deterrence and reassurance efforts. In early February 2022, the United States deployed approximately 4,700 personnel of the 82nd Airborne Division and additional troops from the XVIIIth Airborne Corps to Germany and Poland and repositioned a Stryker squadron from Germany to Romania. Later that month, the DOD deployed the main V Corps Headquarters to Germany and the main 1st Infantry Division Headquarters and the 1st Infantry Division Artillery Headquarters to Poland, which totaled approximately 1,300 soldiers. The United States also deployed additional forces — including an infantry battalion task force, F-35 strike fighters, and attack aviation — to countries along NATO’s eastern flank. By the beginning of Russia’s invasion on February 24, 2022, the U.S. presence in Europe had increased to 90,000 personnel.

Following the invasion, the DOD announced that it had deployed or extended over 20,000 additional forces to Europe, bringing the total number of U.S. personnel in Europe to over 100,000. These forces included the deployment of an ABCT, a High-Mobility Artillery Rocket System (HIMARS) battalion, and KC-135 refueling aircraft, among other forces. At the Madrid NATO Summit in July 2022, President Biden announced several “long-term commitments to bolster European security,” including:

• In Poland, the permanent forward-stationing of the V Corps Headquarters Forward Command Post, an Army garrison headquarters, and a field support battalion;

• In Romania, the deployment of an additional rotational BCT;

• In the Baltics, enhanced rotational deployments;

• In Spain, an increase in the number of destroyers stationed at Rota from four to six;

• In the United Kingdom, the forward-stationing of two F-35 squadrons;

• In Germany, the forward-stationing of an air defense artillery brigade headquarters, a short-range air defense battalion, a combat sustainment support battalion headquarters, and an engineer brigade headquarters; and

• In Italy, the forward-stationing of a short-range air defense battery.

The U.S. force posture in Europe rose by almost 60 percent from its historic low point in 2013. This increase coincided with an expanded footprint on the continent, with forward operating and training sites in addition to traditional bases and garris Europe. U.S. Army Europe and Africa has eight main operating bases across Germany, Belgium, and Italy, supported by seven Army garrison. It additionally maintains forward operating sites and training locations in Estonia, Latvia, Lithuania, Poland, Hungary, Romania, and Bulgaria.

The U.S. Air Forces in Europe-Air Forces Africa (USAFE-AFAFRICA) is headquartered at Ramstein Air Base in Germany and oversees approximately 35,000 personnel (including active-duty, guard, reserve, and civilian) and 217 aircraft. USAFE-AFAFRICA’s capabilities include fighter, attack, rotary-wing, tanker, and transport aircraft which perform close air support, air interdiction, air defense, in-flight refueling, long-range transport, and support of maritime operations. The command operates from seven main bases, including Royal Air Force (RAF) Lakenheath and RAF Mildenhall in the United Kingdom; Ramstein and Spangdahlem Air Bases in Germany; Aviano Air Base in Italy; Lajes Field in the Azores; and Incirlik Air Base in Turkey. While U.S. F-35 squadrons are primarily stationed at RAF Lakenheath in the United Kingdom and Sangadahlem Air Base in Germany, the fifth-generation aircraft deployed to the Baltic and Black Sea regions for air policing missions to deter against Russian aggression.

The U.S. Navy’s Sixth Fleet, U.S. Naval Forces Europe-Africa, oversees an area of responsibility that covers approximately half of the Atlantic Ocean, from the Arctic Ocean to the coast of Antarctica, as well as the Adriatic, Baltic, Barents, Black, Caspian, Mediterranean, and North Seas. The fleet is headquartered at Naval Support Activity (NSA) Naples, Italy. Notably, the Sixth Fleet maintains Task Force 65/Destroyer Squadron 60 in Rota, Spain, which includes the forward stationing of six destroyers.

NATO POSTURE AND THE 2022 STRATEGIC CONCEPT

NATO responded to Russia’s annexation of Crimea in 2014 by establishing a high-readiness response force and enhancing its forward presence with four battlegroups in Estonia, Latvia, Lithuania, and Poland. These four battlegroups, led by the United Kingdom, Canada, Germany, and the United States, respectively, totaled 4,530 personnel by May 2017. NATO’s presence on its eastern flank has expanded considerably since Russia’s second invasion of Ukraine, with four new battlegroups in Bulgaria, Hungary, Romania, and Slovakia, for a total presence of 10,232 personnel as of November 2022. NATO has also adopted an increased air and missile defense posture on the eastern flank, which it refers to as “air shielding.”

At its Madrid summit in June 2022, NATO announced a new strategic concept in response to Russia’s aggression. The new concept calls for a “fundamental shift to [NATO’s] deterrence and defence” by expanding NATO forces and capabilities. This shift includes the expansion of the forward-deployed battlegroups to brigade-sized units “where and when required.” NATO leaders also agreed to a new NATO Force Model for the high-readiness response force, with the goal of growing from 40,00 to over 300,000 troops. The NATO Force Model envisions two tiers of high-readiness forces, including 100,000 personnel ready to deploy within 10 days and an additional 200,000 ready within 30 days. The 2022 NATO Strategic Concept also stresses the importance of enhancing prepositioned equipment to maintain readiness. This development marks a shift in NATO posture away from a “forward-presence tripwire” of limited forces on the eastern flank to a more credible force capable of deterrence by denial. In addition to releasing its new strategic concept at the Madrid summit, NATO also invited Finland and Sweden to join the alliance following the submission of their official letters of application in May. Finland officially joined NATO on April 4, 2023.

In July 2023, NATO took further steps to enhance its posture by establishing new regional plans to defend NATO across all of its flanks with new command and control arrangements and by establishing a new Allied Reaction Force. Allies also agreed through a new Defense Investment Pledge to spend at least 2 percent of GDP on defense in an update to the 2014 agreement.

CONCLUSION

Since the end of World War II, the United States’ military posture in Europe has been impacted by a range of factors, especially the threat posed by the Soviet Union and then Russia. While the end of the Cold War and the collapse of the Soviet Union contributed to a major decline in U.S. forces in Europe, Russia’s brutal invasion of Ukraine has raised numerous questions about the future. The next chapter examines the threat landscape in Europe through 2030.

CH. 03

EUROPE’S EVOLVING THREAT LANDSCAPE

This chapter examines the evolving threat landscape in Europe. It focuses on the military balance with Russia, which is the most significant threat to Europe in the foreseeable future. It also briefly examines terrorism, Iran, China, illegal migration, and other threats, such as pandemics and climate change. Applying a planning horizon through 2030 is far enough away to be helpful to policymakers considering force posture decisions, which can take years to develop. It is also near enough to make plausible assumptions about the future.

The chapter argues that Russia will remain the most significant threat to Europe for the foreseeable future. Today, NATO enjoys a strong conventional and nuclear deterrent. In the event of a potential near-term Russian attack against NATO’s eastern flank, however unlikely, there are several factors in NATO’s favor: the inherent advantage of the defense, the force-to-space ratio problem for Russia, limited avenues of approach from Russia into Eastern Europe, and the qualitative superiority of NATO forces. In addition, NATO retains a robust nuclear deterrent.

Nevertheless, Russia has the will and intentions to threaten one or more NATO countries, and it is re-building its capabilities. Russian military thinking is dominated by a view that the United States is — and will remain — Moscow’s main enemy (главный враг) for the foreseeable future. This view of the United States as the main enemy has increased since the 2022 invasion. Russian political and military leaders assess that Russia’s struggles in Ukraine have been largely due to U.S. and broader NATO aid, which Russian leaders interpret as direct participation in the war. In addition, Russian leaders believe that the United States is attempting to expand its power, further encircle Russia, and weaken Russia militarily, politically, and economically. These sentiments make Russia a dangerous enemy over the next several years and will likely drive Moscow’s desire to reconstitute its military as rapidly as possible, prepare to fight the West if deterrence fails, and engage in irregular and hybrid activities.

In addition, several factors could change the military balance in Europe over the next decade. First, the United States could become overstretched due to a major theater war in another region, such as against China in the Indo-Pacific. European conventional and logistical capabilities are limited — particularly for high-end war — creating potential vulnerabilities if the United States were to withdraw significant air, naval, and ground forces from the region. Second, Russia could rebuild its military capabilities over the next several years with help from China, Iran, North Korea, and other countries. China, in particular, is developing significant military capabilities, such as fifth- and sixth-generation fighters, hypersonic weapons, and emerging technologies, which could change the European balance of power if there were a notable increase in defense cooperation with Russia. Third, U.S. or European political will could erode to build sufficient military capabilities to deter Russia, based on differences in strategic culture, domestic financial and popular constraints, distinct threat perceptions, or other factors. Fourth, there are several other potential wildcards that could impact the threat environment, such as a Russian leadership change or use of a nuclear weapon.

There are several caveats in conducting any analysis of the future security environment, including the military balance. One is that this analysis is based on open-source reporting, not classified intelligence, which creates some gaps. For example, there is imperfect information about the size, composition, equipment, and capabilities of Russian forces, what is known as “order of battle.” Russia has utilized maskirovka — or denial and deception — to mask its activities, strengths, and vulnerabilities. It is also difficult to foresee how the future threat environment will evolve. For example, it was unclear in February 2021 that Russia would invade Ukraine a year later — and then suffer a series of battlefield losses. These uncertainties suggest that any analysis of the future security environment in Europe should have sufficient modesty and humility.

The rest of this chapter is divided into four sections. The first examines the military balance in Europe with Russia. The second section assesses other threats to Europe, such as terrorism, Iran, China, and illegal immigration. The third outlines possible wildcards that could change the military balance in Europe and impact the threat environment. The fourth section provides a brief summary.

MILITARY BALANCE IN EUROPE

This section begins by examining Russia and the conventional balance in Europe and then turns to the nuclear balance

The Conventional Balance

Any analysis assessing the military balance should begin by positing the goals and strategies of the two sides, and it should then proceed to explore the ability of each side to execute its strategy. In Eastern Europe, NATO’s primary goal is to deter an attack and defend its eastern flank, if necessary. To achieve this goal, NATO has adopted a conventional strategy that aims, in the words of NATO’s 2022 Strategic Concept, to “defend forward with robust in-place, multi-domain, combat-ready forces, enhanced command and control arrangements, prepositioned ammunition and equipment and improved capacity and infrastructure to rapidly reinforce any Ally, including at short or no notice.”

Russia’s strategy has generally focused on “active defense” (активная оборона), which involves taking measures to deny victory in the initial period of a foreign invasion. But Russia’s strategy envisions occasionally shifting to the offense, as it did in Ukraine. Vladimir Putin seeks a growing sphere of influence in Europe, the Middle East, and other regions, and he has expressed admiration for the historical Russian Empire and Russian conquerors such as Peter the Great and Catherine the Great. In his essay “On the Historical Unity of Russians and Ukrainians,” Putin argued that Belarusians, Russians, and Ukrainians are descendants of the Rus and that Ukraine has never been a sovereign country. Putin has also expressed interest in a new Slavic union composed of Belarus, Ukraine, Russia, and perhaps the northern part of Kazakhstan.

Based on this revisionist worldview, NATO countries need to deter future Russian activity — including irregular or gray zone activities — in Eastern Europe, especially such countries as the Baltic states, Finland, and Poland. Russian military thinking is dominated by a view that the United States — and NATO more broadly — is Moscow’s main enemy (главный враг). Russian political and military leaders assess that the country’s struggles in Ukraine have been largely due to U.S. and broader NATO assistance. As one senior Russian diplomat remarked, “The United States became a direct participant of this conflict long ago, and they have long been waging a hybrid war against my country. Ukraine is only an instrument in their hands, a tip of the spear held by the U.S.-led collective West. Their goal is to destroy a sovereign, independent Russia as a factor in international politics.” Russian leaders also believe that the United States is expanding its influence, attempting to further encircle Russia, and trying to weaken Russia militarily, politically, and economically. The result is that Russia’s insecurity and animosity toward the West — and the United States in particular — will likely deepen.

While a Russian conventional attack against NATO countries, such as the Baltic states, is unlikely today, NATO needs to deter a Russian attack in the future. There are several factors that are important to assess deterrence: (1) the relative strength of the available forces possessed by Russia and NATO; (2) the force-to-space ratio; (3) the relative rate at which each side can marshal and deploy forces; (4) the individual initiative and flexibility of Russian commanders; and (5) the character of the terrain in the theater.

Relative Capabilities of Opposing Forces: The first factor is the relative strength of the opposing forces. The best measures of relative conventional strength are those that capture the full range of combat capabilities of a force.

While Russian soldiers have struggled in Ukraine, the Russian military is attempting to modernize its forces, including main battle tanks (such as the T-14 Armata), infantry fight vehicles (such as the BMP-2M and T-15), armored personnel carriers (such as the BTR‐82A and BTR‐82AM), and artillery (such as the 300-mm 9K515 Tornado-S [Smerch] and 122-mm 9K51M Tornado-G [Grad] multiple rocket launcher system). Russia is also modernizing its legacy aircraft, surface-to-air missile systems, and radars. Over the next year or two, Russia plans to deploy two regiments equipped with RS-26 Avangard hypersonic glide vehicles. Russia’s navy is modernizing elements of its fleet, including with the Borey-class (Project 955/955A) ballistic missile submarine, guided missile submarines such as the Project 949A Oscar II-class), and missiles (such as the 3M14 Kalibr land-attack cruise missile). Russia is also focused on improving other components of its anti-access and area denial (A2/AD) capabilities through 2030, including air defense, coastal missiles, and layered defenses. Russia’s defense industry, which has been handicapped by sanctions, will likely be under stress to match its leaders’ ambitions, though it is producing new equipment.

Russia is in the midst of a shift in force design. The Russian army will likely continue to move away from battalion formations to infantry, marine, and airborne divisions. This would mark a significant shift away from the changes implemented under former minister of defence Anatoly Serdyukov, who scrapped the Soviet-era structure of the armed forces that included large divisions as part of the “New Look” reforms.

As part of its restructuring plan, the military re-established the Moscow and Leningrad Military Districts as joint force strategic territorial units within the armed forces. This was another blow to the Serdyukov “New Look” reforms, since he had condensed six military districts into four, as well as changed their command and control relationships. The Western Military District’s failure during the invasion of Ukraine may have contributed to its downfall. The Russian military will also likely increase the number of contract service members, or kontraktniki (контрактники), and raise the age ceiling for conscription.

Yet the Russian military faces several challenges. First, Russia’s deepening economic crisis will somewhat constrain its efforts to expand the quantity and quality of its ground, air, and naval forces. The war in Ukraine has fueled Russia’s worst labor crunch in decades; hundreds of thousands of workers have fled the country or have been sent to fight in Ukraine, weakening an economy weighed down by economic sanctions and international isolation. Second, corruption remains rampant in the Russian military, which could undermine Moscow’s overall plan to structure, staff, train, and equip its forces. Third, Russia’s defense industrial base faces several challenges. One is replacement of losses from the war in Ukraine. A protracted war in Ukraine will likely compound these challenges. In addition, economic sanctions have created shortages of higher-end foreign components and forced Moscow to substitute them with lower-quality alternatives.

In short, the conventional balance in Europe favors the United States and Europe today. This advantage includes forces currently deployed to NATO’s eastern flank, as well as forces that Russia and NATO could deploy as part of a war that are stationed elsewhere. As Figure 3.1 highlights, for example, the United States and other NATO forces have a significant advantage in the number of active and reserve army personnel, main battle tanks, other armored fighting vehicles, armored personnel carriers, artillery, and air and missile defenses already deployed on the collective territory. This importantly does not include the potential reinforcements and rotational positioning that U.S. and allied forces can produce. Russia’s war in Ukraine significantly deteriorated Russian capabilities.

In addition, the United States and other NATO forces have some advantages in naval capabilities, including submarines, aircraft carriers, cruisers, destroyers, and other surface ships, as highlighted in Figure 3.2. The same is true in air forces, as highlighted in Figure 3.3, where the United States and NATO have an advantage in bombers, fourth- and fifth-generation aircraft, command and control aircraft, electronic warfare, and other aircraft.

There are two other themes of note based on the data. First, the United States’ armed forces constitute a majority of NATO’s overall military capabilities. As discussed later in this chapter, U.S. involvement in a war in the Indo-Pacific, Middle East, or another region would likely impact the type and number of forces available in Europe, potentially changing this balance. Second, while the conventional balance in Europe heavily favors NATO, Russia’s weakness is particularly apparent compared to Chinese capabilities. As highlighted later in this chapter, China could provide weapons systems and technology to Russia that would change the balance.

Force-to-Space Ratio: A second factor includes force-to-space ratio constraints. The size of the forces that both sides can place on the front lines is limited by the nature of the local geography and the transportation infrastructure. Beyond a certain number, more forces will not fit on the front. Many of the attacker’s vehicles must travel on roads, require significant logistics tails, and need to be spaced out to decrease the possibility of strikes from aircraft, artillery, and ambushes. If the attacker crams too many forces at or near the point of attack, a traffic jam could develop that makes it difficult to maneuver the offender’s armored forces. The defender can place more forces in prepared positions off the roads, but there are limits to the size of the defender’s forward forces as well. This limit, known as the maximum force-to-space ratio, is roughly one brigade per seven kilometers of front, although these are approximate estimates.

Some of these challenges were evident in the first days and weeks following the February 2022 Russian invasion of Ukraine. The Russian army faced significant logistical and maintenance challenges operating in contested areas deep inside of Ukraine. Without access to rail transport infrastructure that is typically used to move Russian heavy equipment and with the few roads available clogged with traffic, it became increasingly difficult for Russian forces operating on the Kyiv axis to move food, fuel, ammunition, and other supplies to forward-deployed forces. These problems were compounded by the Russian army’s failure to provide convoy security to logistics vehicles, such as trucks carrying food, water, fuel, medical equipment, mobile kitchen equipment, and spare parts. Forward-deployed Russian vehicles broke down, but many had to be abandoned because of a lack of spare parts, mechanics, and recovery vehicles. The Russian military also lacked modern shipping containers, mechanized loaders, forklifts, or pallets to efficiently move supplies into Ukraine. Instead of a mechanized logistics system, Russia’s military relied on conscript labor to move gear, often in unwieldy wooden crates.

▲ Figure 3.1: Military Balance in Selected Land Forces, 2023. Source: International Institute for Strategic Studies (IISS), The Military Balance 2023 (London: Routledge, 2023).

▲ Figure 3.2: Military Balance in Selected Maritime Forces, 2023. Source: IISS, The Military Balance 2023.

Force-to-space ratio constraints generally help the defender — in this case NATO — by preventing the attacker from exploiting whatever local materiel superiority might be enjoyed at breakthrough points. The attacker strives to achieve overwhelming superiority at the breakthrough points by suddenly concentrating forces there. An attacker likely requires a local force advantage of at least 3:1 to open a breach in the defender’s front. If both sides have large forces at their disposal, however, the attacker may be unable to place enough units forward to gain a 3:1 advantage, even if it has local materiel superiority, simply because there is insufficient room at the front. Instead, the attacker must stack forces up behind the front, where they cannot contribute to the breakthrough battle. But stacking forces up puts them in danger of being targeted by long-range strike.

Russia faces considerable force-to-space ratio constraints in Eastern Europe today. A Russian buildup along NATO’s eastern flank, including in Belarus, would likely lead to a rapid NATO deterrent buildup in response — and deny Russia from gaining a force-to-space ratio advantage.

Relative Rates of Reinforcement into Breakthrough Area: A third factor affecting the balance is the relative rate of reinforcement into the breakthrough battle area. The defender must match the attacker’s concentration at the main point of attack. To do this, the defender — in this case NATO forces — must be able to move forces already in the theater. The defender must also be able to compete with the attacker in bringing outside forces into the theater. The defender’s basic aim is to ensure that the attacker does not win the breakthrough battle by wearing down the defender to the point where the defender has virtually no forces remaining.

In most wargames over the past decade involving a Russian invasion in Eastern Europe — especially the Baltics — forward-deployed NATO ground forces were badly outgunned by Russia both by forces massing from mainland Russia but also from the heavily militarized enclave of Kaliningrad, located on the Baltic Sea between Lithuania and Poland. NATO airpower was able to impose significant attrition on attacking Russian forces, destroying the equivalent of two to three battalion equivalents per day in some games. But without a heavy NATO ground force to slow down Russian forces, NATO forces failed to halt the invasion. More recently, however, NATO has strengthened its eastern flank, improving its relative rate of reinforcement. For example, the Baltic region has been a focal point for NATO, which agreed on the Readiness Action Plan at the 2014 Wales summit and established the Enhanced Forward Presence at the 2016 Warsaw summit. This forward presence was first deployed in 2017, with the creation of four multinational battalion-size battlegroups in Estonia, Latvia, Lithuania, and Poland, led by the United Kingdom, Canada, Germany, and the United States, respectively. In the southeast, a tailored presence on land, at sea, and in the air contributed to increased allied activity in the region as well as enhanced situational awareness, interoperability, and responsiveness.

▲ Figure 3.3: Military Balance in Selected Air Forces, 2023. Source: IISS, The Military Balance 2023.

Following Russia’s invasion of Ukraine in February 2022, NATO reinforced the existing battlegroups and established four more multinational battlegroups in Bulgaria, Hungary, Romania, and Slovakia. Known as the Eastern Flank Initiative, this brought the total number of multinational battlegroups to eight, effectively doubling the number of troops on the ground when fully established and extending NATO’s forward presence along the alliance’s eastern flank — from the Baltic Sea in the north to the Black Sea in the south.

The four northeastern battlegroups (in Estonia, Latvia, Lithuania, and Poland) are under NATO’s Multinational Corps Northeast Headquarters in Szczecin, Poland. Two division-level headquarters coordinate the training and preparation activities of their respective battlegroups. Multinational Division Northeast Headquarters, located in Elblag, Poland, has been fully operational since December 2018. This headquarters works closely with the battlegroups in Poland and Lithuania. A complementary Multinational Division North Headquarters was activated by NATO in October 2020 and is moving toward full operational capability. Its forward elements are located in Adazi, Latvia, while the rest of the headquarters is located in Karup, Denmark. This headquarters cooperates closely with the battlegroups in Estonia and Latvia. At the 2022 NATO summit in Madrid, NATO allies agreed to enhance the multinational battlegroups from battalions up to brigade size, where and when required. These steps have changed the relative rates of reinforcement, making it more difficult for Russia to conduct a successful breakthrough.

In addition, an attacker’s penetrating armies will be vulnerable to counterattack since they will be moving forward rapidly on unfamiliar terrain at the head of long logistical columns. The defender therefore may be able to seal off the penetration if it rapidly brings reserves to bear. The size and quality of the defender’s reserves become important for this reason. Again, NATO has made adjustments over the past several years. NATO’s rapid reinforcement strategy ensures that forward-presence forces will be reinforced by NATO’s Very High Readiness Joint Task Force (VJTF), the broader NATO Response Force, additional high-readiness forces, and NATO’s heavier follow-on forces. At the 2022 Madrid summit, NATO agreed on a new NATO Force Model, which represented a broader expansion of high-readiness forces potentially available to NATO, where and when required. NATO allies have also agreed to boost NATO’s ability to reinforce its forces in the east by developing:

• More prepositioned equipment and weapons stockpiles;

• More forward-deployed capabilities, including integrated air and missile defense systems;

• Strengthened command and control; and

• Upgraded defense plans, with specific forces preassigned to the defense of specific allies.

Flexibility and Initiative of Attacking Forces: The fourth factor is the ability of attacking forces to maximize flexibility and initiative. To forestall a successful counterattack, the attacker must take immediate advantage of the breakthrough opening and then maintain a rapid rate of advance to keep the defender constantly off balance. This is a demanding task because the commanders of the attacker’s forces, operating in a fog of war, will have to make rapid-fire decisions based on incomplete information while facing a constantly changing situation. A deep strategic penetration is best served by a flexible command and control structure and a joint force commanded at all levels by individuals capable of intelligently exercising initiative. Delegating responsibility to officers and non-commissioned officers who can make bold decisions in difficult circumstances maximizes the prospects that the attacking forces will not get bogged down, undermining the blitzkrieg.

Russian forces currently lack flexibility and initiative. During the February 2022 invasion of Ukraine, for example, a failure of small-unit cohesion and initiative likely contributed to the defeat of some Russian forces. Russian units included a mix of troops with variable levels of training, experience, and equipment — and with little time spent working together. The lack of a professional non-commissioned officer corps in the Russian army likely inhibited the cohesion of these units. Additional deficiencies included small-unit tactics and morale, which are usually the purview of junior and non-commissioned officers. Small-unit leaders failed to break with the Soviet tradition of passively waiting for orders, which discourages initiative and punishes mistakes. It did not help that many Russian soldiers were not informed that they were being sent to war, but were instead told they were headed to a training mission. Furthermore, the massive casualties among Russia’s contract soldiers — disproportionately concentrated among the airborne and special forces — in the first month of the war left many surviving soldiers deeply reluctant to embark on offensive operations. The most experienced troops who should have been critical to leading newly mobilized personnel were, in many cases, the most reluctant to conduct attacks.

Consequently, the Russian military — especially Russian ground forces — lacks sufficient initiative to be able to effectively execute a conventionally focused blitzkrieg operation against NATO countries.

Geography: Geography is a fifth factor impacting the outcome of a successful breakthrough battle. The defender generally prefers a front covered with obstacles — rivers, mountains, forests, swamps, jungles, and prepared defensive positions — so that there are few locations where the attacker can place a main axis of attack. The defender then has a good chance of predicting where the attacker will strike, minimizing the attacker’s prospects of outmaneuvering the defender. Also, a defender faced with few possible breakthrough points along the front can concentrate forces in front of them, since the defender does not have to worry much about the obstacle-ridden portion of the front.

Geography poses a challenge for NATO in Eastern Europe, though it does not outweigh other factors, such as both sides’ relative capabilities and the attacker’s initiative. The Baltic states, for example, are largely flat, though the terrain is dotted with lakes, bogs, and marshes. In some places, off-road mobility could be difficult, especially during the rasputitsa — or thaw — when travel on unpaved roads becomes difficult because of muddy conditions caused by rain or melting snow. Still, there is a fairly robust network of roads and highways in the Baltics, and the distances are short.

It is only 213 kilometers from Ivangorod, Russia, which is situated along the Russian-Estonian border, to Talinn along the E20 highway in flat terrain. Lithuania is in an even more precarious situation. There are multiple direct routes from Belarus to Vilnius, Lithuania’s capital, in relatively flat terrain. It is a short 35-kilometer drive from the border crossing at Kamenny Log to Vilnius along the E28 highway, and a 34-kilometer drive from the border crossing at Kotlovka to Vilnius along the 103 highway. Russia’s enclave in Kaliningrad could interfere with the movement of NATO forces into the Baltics. To move from Poland into Lithuania by land, for example, NATO forces would have to transit the “Kaliningrad corridor,” a 110- to 150-kilometer gap in Poland between the Russian enclave of Kaliningrad and Belarus that could be attacked from both sides and could require substantial air, sea, and ground forces to secure. Instead of moving over land from Poland, NATO forces could arrive by air or by sea, but they would have to contend with Russian interdiction.

Finland, which shares a 1,300-kilometer border with Russia, also presents a challenge for NATO. Finland’s geography is characterized by intermingled boreal forests and lakes, with archipelagoes and coastal lowlands in the south, a slightly higher central lake plateau, and uplands in the north and northeast. Northern and eastern Finland are sparsely populated and contain vast wilderness areas, with taiga forest as the dominant vegetation type. But the terrain in Finland is mostly flat, and it is only 191 kilometers from the Torfyanovka border crossing to Helsinki along the E18 highway.

The same is true of Poland, whose plains have made it susceptible to invasion throughout history, from the Mongols in the thirteenth century to the Nazi and Soviet invasions in the twentieth century. Poland’s geographic location is, in part, why Norman Davies titled his history of Poland God’s Playground. Poland’s relatively flat central terrain is partly why wargames of a Russian invasion of Poland, including Winter-20, have been bleak.

While these geographic features present challenges, they do not outweigh the other factors, such as the relative capabilities of the forces possessed by the sides, the force-to-space ratio, the relative rate at which each side can marshal and deploy reinforcements, and the individual initiative and flexibility of the attacker’s commanders. The conventional balance heavily favors NATO, which has a very good chance of defeating any conventional Russian attack in Eastern Europe. This reality is very different from the military balance in Central Europe for part of the Cold War.

The Nuclear Balance

Russia has improved its nuclear capabilities and still maintains the largest inventory of strategic weapons in the world, providing it with a strong deterrent capability against conventional and nuclear threats. Moscow has been — and will likely continue to be — committed to retaining a full range of sea-, land-, and air-based systems. Russia’s land‐based intercontinental ballistic missiles (ICBMs) are under the control of the Strategic Missile Forces, while sea‐ and air‐based strategic systems are operationally managed by the Russian navy and air force. Russia’s Aerospace Forces (VKS) brings together Russia’s aviation, air defense, and missile defense systems, as well as the country’s missile early-warning and space control and monitoring systems, under a unified and integrated command and control structure. Moscow may also be developing a nuclear space-based weapon capable of targeting satellites.

Overall, examples of Russian modernization priorities include: the RS-26 Avangard ICBM, equipped with a hypersonic glide vehicle; the RS-28 Sarmat ICBM; the Poseidon nuclear-capable, long-range unmanned underwater vehicle; the Kh-47M2 Kinzhal (Dagger) air-launched high-speed ballistic missile; the Tu-160M strategic bomber; and the PAK-DA next-generation strategic bomber.

As Figure 3.4 highlights, however, the United States and NATO possess a strong nuclear deterrent. The United States has roughly 400 Minuteman III ICBMs. In addition, the U.S. arsenal includes roughly 280 Trident II D-5 submarine-launched ballistic missiles (SLBMs), the United Kingdom has another 48 Trident I/II D5 SLBMs, and France has 64 M51 SLBMs. In addition, the United States currently possesses roughly 66 aircraft (B-2s and B-52s) capable of carrying nuclear weapons, while France has 40 Rafales. The certification of the F-35 as a dual-capable aircraft (DCA) will increase the number of tactical air delivery systems available in Europe. The result is near parity in the number of warheads: approximately 4,495 for Russia and roughly 4,300 for the United States, United Kingdom, and France. NATO’s strategic air-, land-, and maritime-based capabilities give it a viable second-strike capability and a strong deterrent.

▲ Figure 3.4: The Nuclear Balance in Selected Strategic Offensive Weapons, 2023. Source: IISS, The Military Balance 2023.

The United States is also modernizing its nuclear arsenal. For example, existing strategic delivery systems are undergoing modernization, including complete rebuilds of the Minuteman III ICBM and Trident II SLBM. The service lives of the Navy’s 14 Trident Ohio-class ballistic missile submarines are being extended. Additionally, Columbia-class submarines will replace Ohio-class ballistic missile submarines. The U.S. Air Force is also building a new strategic bomber, the B-21 Raider, and a new nuclear-capable cruise missile, the Long Range Stand Off Weapon, to replace the existing air-launched cruise missile. These modernization efforts will likely ensure that NATO retains a strong nuclear deterrent in Europe.

While NATO enjoys a robust nuclear deterrent, it is less clear whether Russia will be deterred from using nuclear weapons against a country outside of NATO, such as Ukraine. Any Russian use of nuclear weapons against any non-NATO country would cause significant political concern across Europe.

Other Threats

In addition to Russia, there are other threats to Europe. This section focuses on several threats: Iran, China, terrorism, illegal immigration, and illegal drug trafficking. These represent the most acute threats to Europe over the next decade. There are other threats — involving climate change, pandemics, energy, and cyber — that also present long-term threats.

Iran: European states will likely face a lingering threat from Iran, including from long-range missiles. Under the oversight of the Islamic Revolutionary Guard Corps Aerospace Forces, Iran will likely continue to field more accurate and longer-range missiles over the next decade, as Figure 3.6 highlights. A ballistic missile based on Iran’s Zoljanah space launch vehicle could carry a one-ton warhead as far as 5,000 kilometers, allowing Iran to strike every European capital. These developments will supplement other Iranian missiles, such as the Shahab-3 and Khorramshahr medium-range ballistic missiles, which have an operational range of up to 2,000 kilometers. Iran also has layered area denial and anti-surface warfare capabilities, including naval mining (such as moored contact, drifting contact, and limpet mines), small boat swarming tactics, and coastal defenses.

However, there are serious challenges with Europe’s integrated air and missile defense capabilities, particularly in ground-based air defense, command and control, and defense against emerging advanced threats. The European Sky Shield Initiative, which is led by Germany, could theoretically address some of these problems. But it is under significant political pressure, and several countries, such as France, Poland, and Italy, have opted out of the initiative. The result is that European missile defense capabilities are a poorly integrated jumble of capabilities. For example, France and Italy possess SAMP/T ground-based air defense missile systems; Germany and the Netherlands have the Patriot surface-to-air missile system; and Greece and Romania have Patriot, SA-20, and I-HAWK systems. There are numerous future plans in the works. For instance, NATO’s ballistic missile defense program is unlikely to be fully operational until roughly 2030. Most of the European countries developing sea-based, lower-layer ballistic missile defense are forecasting delays — including to the development of a suitable interceptor missile — through the end of the decade. The U.S. contribution to NATO’s ballistic missile defense architecture will remain critical, including the Aegis Ashore and periodic rotation of the Terminal High Altitude Aerial Defense (THAAD) missile defense system.

China: Security competition between the United States and China has increased — and will likely continue to increase over the next decade. But there are different views of the Chinese threat in European capitals.

The United Kingdom, for example, has been critical of China’s crackdowns in Hong Kong, has been willing to speak out about China’s human rights abuses, and is increasingly vocal about the threat from China. The head of MI5, the United Kingdom’s domestic intelligence agency, bluntly remarked in 2022 that the “most game-changing challenge we face comes from the Chinese Communist Party. It’s covertly applying pressure across the globe.” France, which has overseas departments, territories, and communities in the Indo-Pacific, has established a harder line against China than many European countries. In addition, Denmark’s economic relationship with China is limited, and its leaders have been wary of Chinese intentions in Greenland and the Arctic. Denmark joined the U.S.-led Export Controls and Human Rights Initiative, alongside Australia, Canada, France, the Netherlands, Norway, and the United Kingdom, which is designed to stem the flow of sensitive technologies to authoritarian governments such as China. Lithuania has faced economic coercion from China for its moves to recognize a Taiwanese office in Vilnius as well as for withdrawing from an economic initiative focusing on China and Central and Eastern Europe.

But other European countries have been less concerned about China. Germany’s relationship with China is complicated due to Germany’s dependence on Chinese manufacturing and markets. For example, a study from a German industry association found that “approximately 5,200 German companies comprising over one million employees” were operating in China and that many more had “large sums of investments tied up in China.” This situation has created some German dependencies on Chinese supply chains and value creation networks, and the Chinese shipping giant COSCO bought a 35 percent stake in a container terminal at the port of Hamburg. In Greece, China’s COSCO now owns more than 51 percent of the commercial port of Piraeus, which is often used by NATO for port visits, exercise staging, and transport. This dependency raises questions about whether Greece might hesitate to act (or be constrained from acting) in a conflict with China. Italy has also established close relations with China. For example, Italy signed a memorandum of understanding with China, which is valid until 2024, in support of the Belt and Road Initiative.

A majority of Europeans are opposed to engaging in conflict with China, according to some survey data. Similarly, a majority believe that they are not in any type of a Cold War with China, though a growing percentage also say their views of China have worsened over time and expressed concern about Chinese ownership of key infrastructure. The populations of Sweden and the Netherlands have the most unfavorable views of China, while those of Greece, Hungary, Italy, and several other countries have more favorable views. A substantial percentage of Europeans (36 percent) consider China to be a necessary partner. Only 12 percent of all respondents in one survey saw China as an adversary. Some polling also suggests that a large majority of European populations would prefer to remain neutral in a conflict between the United States and China.

These realities suggest that there are differences among European governments and populations about the perceived threat posed by China. This is an important consideration for U.S. military planners and political leaders: it is not clear nor inevitable that NATO and Europe writ large can be counted on to join military actions in the Indo-Pacific through 2030. And this may be an acceptable outcome in order to maintain some strategic balance against Russia.

Terrorism: Terrorism in Africa, the Middle East, and South Asia will likely present a continuing threat to Europe. Salafi-jihadist groups linked to the Islamic State and al Qaeda are active across these regions. There are several groups linked to al Qaeda, including Harakat al-Shabaab al-Mujahidin (or al Shabaab) in Somalia; Jama’a Nusrat ul-Islam wa al-Muslimin in West Africa; Hay’at Tahrir al-Sham in Syria; Hurras al-Din in Syria; al Qaeda core and al Qaeda in the Indian Subcontinent in Afghanistan; and al Qaeda in the Arabian Peninsula in Yemen. There are also several groups linked to the Islamic State in Iraq and the Levant (Islamic State), including the leadership in Iraq and Syria; the Islamic State in the Greater Sahara in West Africa; Ansar Bayt al-Maqdis in Egypt; the Islamic State-Libya; the Islamic State-Khorasan; the Islamic State-Yemen, Islamic State networks in Somalia, which host the al-Karrar office. In addition, Shia groups, including Lebanese Hezbollah, continue to operate in Europe, though primarily to fundraise and recruit individuals rather than plot attacks. The most significant external terrorist threat to Europe is likely attacks by individuals inspired by the Islamic State or al Qaeda — especially with connections to the Middle East and Africa.

▲ Figure 3.5: Iran’s Ballistic and Cruise Missile Ranges through 2030. Source: Missile Defense Project, “Missiles of Iran,” Missile Threat, CSIS, June 14, 2018, Last modified July 17, 2020; “Identical Letters Dated 7 April 2021 from the Permanent Representative of Israel to the United Nations addressed to the Secretary-General and the President of the Security Council,” United Nations Digital Library, April 8, 2021.

Illegal Immigration: Europe faces a continuing threat from illegal immigration, including human trafficking for all forms of exploitation, such as labor and sexual exploitation. Migrant-smuggling networks transport individuals illegally through the Western, Central, and Eastern Mediterranean and Western Balkans into Europe, requiring extensive monitoring. In 2021, Belarus organized immigrants from the Middle East, including Iraqi Kurdistan, to cross into Poland. It was part of a political coercion campaign by Belarusian president Alexander Lukashenko, who threatened to “flood” the European Union with illegal immigrants and drug traffickers. In response, European countries have been involved in efforts to detect, monitor, and counter the movement of illegal immigrants, including European Union Naval Force Mediterranean, Operation Triton, Operation Themis, and Operation Mare Nostrum.

Illegal Drug Trafficking: European states will likely face persistent threats from illegal drugs and drug trafficking, including from cocaine, heroin, amphetamines, methamphetamines, MDMA, and other drugs. In response, European states are likely to remain focused on detecting, monitoring, and countering the production and trafficking of illegal drugs coming from West and South Asia, South America, North Africa, and other regions. Recent European counter-drug campaigns have included the European Union Military Operation in the Central African Republic and Operation Atalanta.

Other Threats: European states will also face several other threats. One is from pandemics, such as new strains of influenza or a novel coronavirus. Another is from climate change. Concerns about global climate change are likely to remain high in many European countries, as such events as wildfires, floods, and extreme heat cause significant disruption across the continent. Worries about climate change are not shared by all Europeans and are generally lower among those who support far-right populist parties. In Germany, for instance, only 55 percent of supporters of the Alternative for Germany party view climate change as a major threat, compared with 77 percent of those who do not support the party. Similar divisions also appear in Belgium, France, Italy, the Netherlands, Poland, Spain, Sweden, and the United Kingdom. Europe will also continue to face a threat from cyberattacks from a range of state and non-state actors, including China, Russia, and Iran. Finally, Europe will likely face a persistent energy crisis because of a decline in Russian gas deliveries, supply chain disruptions, and volatility in the oil and gas markets.

Possible Wildcards

Despite these threats, Russia will likely remain the most significant threat to Europe in the foreseeable future, and there are several wildcards that could change the conventional military balance in Europe. This section focuses on several possibilities: U.S. involvement in a major war outside of Europe, a Russian military buildup with assistance from China and other countries, and erosion of U.S. or European political will. These are by no means the only possibilities, though they are plausible wildcards that could significantly impact the threat landscape.

Major War Outside of Europe: The United States could become overstretched with a major theater war in another region, such as against China in the Indo-Pacific. European conventional and logistical capabilities are limited — particularly for high-end war — and U.S. involvement in a major war in another region could potentially alter the balance in Europe. One example is a war between the United States and China over Taiwan. There are at least two major implications for Europe.

First, the United States would likely require significant resources in a Taiwan conflict, including air defense systems, such as Patriots; long-range bombers, such as the B-21; long-range precision strike capabilities, such as the Long Range Anti-Ship Missile (LRASM) and Joint Air-to-Surface Standoff Missile-Extended Range (JASSM-ER); and submarines, such as Virginia-class and Columbia-class vessels. Overall, the requirements and political attention necessary for a U.S. war with China in the Indo-Pacific would likely require deploying U.S. Air Force, Navy, Marine Corps, and possibly Army personnel and capabilities to the Indo-Pacific for an extended period. It is likely that a war could be protracted, dragging out for months or longer.

Second, the United States would likely lose a significant portion of its military forces, especially in a protracted war. In the more pessimistic scenario from a recent CSIS wargame, for example, the United States loses nearly 500 aircraft and 14 surface combatant ships. Roughly 90 percent of U.S. aircraft losses occur while they sit on airfields, not in the air. Across scenarios, the United States typically loses more than 500 U.S. aircraft in all, as well as at least two aircraft carriers and between 10 and 20 large surface combatants. These high losses occur because U.S. aircraft and surface ships deploy forward to strike at the Chinese fleet, particularly the amphibious forces, before establishing air and maritime dominance. Chinese losses are also high, with over 300 aircraft losses and over 100 surface combatant ships destroyed. Overall, Chinese air losses varied across the wargame scenarios from several dozen to over 700.

In a Taiwan conflict, the United States would likely have to shift considerable military resources and political focus to the Indo-Pacific and away from Europe. U.S. military power would also be eroded through attrition. This could have at least two consequences. It could change the conventional balance in Europe by requiring the United States to pull some military forces out of Europe and deploy them to the Indo-Pacific. In addition, Russia could be emboldened to conduct offensive actions against the Baltic states, Poland, Finland, or another country. A U.S. withdrawal of forces to another theater, such as the Indo-Pacific, could create a window of opportunity for offensive actions by Russian leaders, who may conclude that the advantages of defense in Europe have weakened. Historically, leaders have developed offensive military strategies when they possess revisionist war aims and believe the balance of power is shifting in their favor.

It is also conceivable that the United States could become involved in a major war elsewhere — such as against North Korea, Iran, or terrorist groups in the Middle East or South Asia — which Russian leaders could attempt to exploit. Following Hamas’ brutal attack against Israel on October 7, 2023, conflict in the Middle East expanded to include Lebanon, Syria, Iraq, Yemen, and other countries.

Russian Military Modernization: Russia could significantly rebuild its conventional capabilities — as well as further invest in asymmetric ones — with help from China and other countries, such as North Korea and Iran. Russia is attempting to reconstitute its land forces to prepare for deterrence and warfighting against NATO. The Russian army will likely continue to move away from battalion formations to infantry, marine, and airborne divisions. This would mark a significant shift away from the changes implemented under former minister of defence Anatoly Serdyukov, who scrapped the Soviet-era structure of the armed forces that included large divisions as part of the “New Look” reforms.

For example, Russian military leaders have indicated an intention to create at least nine new divisions: five artillery divisions, including super-heavy artillery brigades for building artillery reserves; two air assault divisions in the Russian Airborne Forces, bringing its force structure to roughly equal with Soviet times; and two motorized infantry divisions integrated into combined arms forces. The Ministry of Defence will likely transform seven motorized infantry brigades into motorized infantry divisions in the Western, Central, and Eastern Districts, as well as in the Northern Fleet. It will also likely expand an army corps in Karelia, across the border from Finland. In addition, each combined arms (tank) army may have a composite aviation division within it and an army aviation brigade with 80 to 100 combat helicopters under the control of ground force units — not the Russian Aerospace Forces. This decision was likely a result of the poor joint operations in Ukraine, especially air-land battle, though it does not fix poor coordination between Russian land and air forces.

Russian leaders have expressed an interest in strengthening Russian naval forces — including submarines — in response to growing tensions with the United States and NATO. The Ministry of Defence has announced a desire to create five naval infantry brigades for the navy’s coastal troops based on existing naval infantry brigades. This expansion followed Russia’s adoption of a new maritime doctrine in July 2022, which identified the United States and NATO as major threats. In addition, the doctrine expressed an interest in building modern aircraft carriers, though it also highlighted the challenges of Russia’s lack of overseas naval bases and the constraints on Russia’s shipbuilding industry because of the West’s economic sanctions. Senior Russian officials have identified nuclear-powered submarines as critical in future force design.

Beijing could accelerate Russian military modernization. China possesses significant fifth-generation military capabilities, technology, and money that could impact the European balance of power if Beijing calculated that it was in its interest to help Russia modernize its military. The Chinese Communist Party’s 14th Five Year Plan, which goes through 2025, calls for accelerated development of military mechanization, informatization, and “intelligentization.” China is focusing on military applications for such areas as artificial intelligence, autonomous systems, biotechnology, information technology, quantum computing, robotics, advanced materials and manufacturing, and deep-sea technologies.

China is developing the J-20A and J-20B fifth-generation stealth fighter, armed stealth unmanned aircraft systems, and the J-31 medium-weight stealth fighter by 2025. China is also developing kinetic kill vehicle technology to field an upper-tier ballistic missile interceptor by 2030; longer-range, more accurate, and increasingly lethal ballistic and cruise missiles; air defenses; and other platforms and systems. The People’s Liberation Army Navy (PLANAF) is fielding new carrier-based aircraft, as well as anti-submarine warfare, helicopters, unmanned aircraft, land-based maritime strike, and air defense forces. China may have as many as five aircraft carriers by 2030, aided by helicopter carriers and a fleet of destroyers. The development of China’s space, counterspace, and electronics sectors has enabled it to increase the pace of satellite launches and deploy a wider range of sophisticated intelligence, surveillance, and reconnaissance (ISR) satellites. Some modeling suggests that the effectiveness of the Chinese submarine fleet (as measured by the number of attack opportunities it might achieve against carriers) has risen significantly over the past 25 years.

Based on these developments, China could potentially provide significant air, land, and maritime weapon systems and technology to Russia through exports, joint development projects, funding, or other arrangements that facilitate a Russian defense revitalization. After all, Russia and China have pledged to deepen defense cooperation through arms sales, military exercises, and other activities.

Eroding Political Will: An erosion of European — or U.S. — political will could weaken NATO’s cohesion and threaten its ability to project and conduct credible deterrence. Political will refers to the proclivity and decision of political leaders to conduct activities, including military activities. Politics and war are deeply intertwined. As the Prussian general and theorist Carl von Clausewitz argued, “war is not merely a political act, but also a real political instrument, a continuation of political commerce, a carrying out of the same by other means.” For Clausewitz, will is an essential component of military operations: “If we desire to defeat the enemy, we must proportion our efforts to his powers of resistance. This is expressed by the product of two factors which cannot be separate, namely, the sum of available means and the strength of the Will.”

In addition, economists and political scientists who study the logic of collective action have identified burden sharing as a persistent problem in multinational organizations. Larger, richer allies step up to provide a public good, which leads to free-riding behavior by smaller, less wealthy allies. For NATO, deterrence and collective defense became that public good during the Cold War. During this period, there was a close correlation between allies’ GDPs and their respective levels of defense spending. Larger allies were willing to tolerate a degree of free riding in light of the existential, overarching threat posed by the Soviet Union.

Several factors — such as strategic culture, domestic constraints, voluntary force recruitment challenges, technology usage concerns, differences in threat perception, or even an economic depression — could undermine the political will of European countries or the United States to sufficiently deter Russia. For example, domestic constraints can undermine political will. They can be political, such as the degree of fragmentation within a government or friction between different elements in the bureaucracy. The former is particularly problematic in Europe, where coalition or minority governments are becoming the norm rather than the exception. Some countries attempt to reduce fragmentation and limit “ministerial drift” by locking in their priorities and policies through formal coalition agreements (e.g., Germany) or cross-party defense agreements (e.g., Denmark).

Domestic constraints on political will can also be structural. These include legal limitations on deployment of forces, requirements for parliamentary approval to deploy forces, and operational caveats on deployments. In Afghanistan, only a few countries (such as Denmark, Georgia, Poland, the United States, and the United Kingdom) operated caveat-free, with most imposing restrictions on everything from the rules of engagement to the geographic areas in which their forces were able to operate. Legal limitations on the deployment of forces, requirements for parliamentary approval to deploy forces, domestic politics and logrolling, and imposition of operational caveats on deployments and the use of certain technologies will remain a challenge for some European countries and could impact their willingness to build sufficient capabilities to deter Russian aggression.

The 2024 U.S. elections also raise major questions about U.S. political will in Europe. It is possible, for example, that Donald Trump could withdraw from NATO in a second term, raising serious questions about credible deterrence against Russia.

Other Wildcards: There are several other wildcards that could change the balance in Europe or otherwise impact the threat landscape. First, Russia could successfully use an irregular or a limited aims strategy in Eastern Europe. The goal of an irregular strategy would be to destabilize one or more European countries through subversion rather than a conventional military campaign. This could include, for example, aiding non-state actors in the Baltic states or other countries — including pro-Russian populations — to cause instability. Moscow adopted this type of a strategy in Eastern Ukraine in 2014. Russia could also adopt a limited-aims strategy and seize only a portion of territory in Europe or Central Asia. Second, a leadership change in Russia could create a more dangerous — or friendlier — neighbor, impacting the threat from Russia. Third, Russia could use nuclear weapons, including battlefield nuclear weapons against Ukraine, breaking the nuclear taboo that has existed since 1945. This would cause significant concerns in European capitals about the threat from Moscow.

CONCLUSION

As the evidence presented in this chapter suggests, NATO likely possesses a strong conventional and nuclear deterrent against a possible Russian threat in the short term. Other potential threats to Europe — such as Iran, China, terrorism, illegal migration, illegal drug trafficking, pandemics, and climate change — do not pose an existential crisis in the near term.

Over the long term, however, Russia will likely constitute a serious threat to the United States and Europe. Russian president Vladimir Putin retains the political will and intentions to expand Russian power abroad, and Russia is reconstituting its military capabilities with help from China, Iran, and North Korea. The military balance could shift, and deterrence could weaken — perhaps significantly — if the United States were to become involved in a major war in the Indo-Pacific or another region, if Russia were able to rearm and rebuild with Chinese and other assistance, or if U.S. or European political will eroded. The key takeaway is that neither today’s military balance nor deterrence is guaranteed ad infinitum. To help understand the future military balance in Europe, the next chapter examines European military capabilities.

CH. 04

EUROPEAN MILITARY CAPABILITIES

This chapter examines European military capabilities. Any analysis of U.S. force posture in Europe needs to assess European military capabilities at present and in the future, which is reflected in NATO’s own 2030 plan from the Brussels summit and the subsequent 2022 Strategic Concept from the Madrid summit. This chapter asks one central question: What types of missions will European allies and partners of the United States be able and unable to effectively perform by 2030?

To answer this question, this chapter uses a combination of methods. It builds an analytical framework that includes a range of military missions, from small-scale humanitarian assistance missions to large-scale combat. The chapter then uses this framework to evaluate the ability of European countries to accomplish these missions. It also builds a data set of specific European operations over the past three decades, including operations conducted through NATO and the European Union. The data provide a useful context for the types and frequency of missions in which European states may engage. Finally, it uses the results and analyses from wargames, scenarios, exercises, after-action reviews, and other analyses to assess the ability of European states to perform military missions through 2030.

Based on the analysis, this chapter makes two main arguments. First, if member states meet their “NATO 2030” goals, most NATO militaries will likely be able to conduct the majority of military missions by 2030 at the lower end of the conflict continuum with little or no U.S. assistance. But European militaries will likely have difficulty conducting operations at the higher end of the conflict continuum without significant assistance from the United States. European states still lack sufficient capabilities in the following areas:

• Combat support, such as short-range air defense and long-range indirect fires;

• Airlift and other logistical means of transporting troops and material;

• Quantity, quality, and capabilities of ground forces, especially heavy maneuver forces;

• Maritime capabilities, including sensors (such as sub-surface sensors) and survivability systems;

• Sufficient quantities of long-range precision strike, such as the Long Range Anti-Ship Missile (LRASM); and

• Multi-spectrum ranges to train and maintain high-readiness forces.

To help make up for some of these shortfalls, Chapter 6 outlines several security cooperation steps to improve European military capabilities. Nevertheless, the most significant obstacle to fixing these capability gaps is a lack of political will in European capabilities.

Second, most European militaries will likely continue to face serious challenges projecting power into regions such as the Indo-Pacific. They lack significantly deployable capabilities in such areas as anti-submarine warfare; intelligence, surveillance, and reconnaissance (ISR); ballistic missile defense; air precision strike; suppression of enemy air defense; and expeditionary logistics. What capabilities European allies do have in these categories should likely be prioritized for a Europe-based fight.

The rest of this chapter is divided into three sections. The first develops a framework for understanding and analyzing military missions. The second section assesses European participation in military missions through 2030. The third section provides a summary of the main conclusions.

FRAMEWORK FOR UNDERSTANDING MILITARY MISSIONS

This chapter focuses on the ability of European militaries to perform a mission, a military task to complete an action with a specific purpose. An important metric of military power is the ability of military forces to successfully prosecute a variety of missions. Military missions are often categorized by their focus. Examples include noncombatant evacuation, foreign humanitarian assistance, security force assistance, freedom of navigation, counternarcotics, counterterrorism, and large-scale combat missions. Military missions are distinct from civilian missions in that they are conducted by military personnel, even if the activities lack a uniquely martial component. In addition, this chapter also discusses military operations, which include specific military actions to carry out strategic, operational, tactical, or other objectives. As used here, missions refer to the general tasks that militaries are asked to perform, while operations refer to specific, named efforts. Named operations include such examples as Operation Allied Force in Kosovo, Operation Unified Protector in Libya, Operation Concordia in the former Yugoslavia, and Operation Sea Guardian in the Mediterranean.

Much of the policy focus on European capabilities has been on tracking quantitative metrics. For example, NATO has collected and analyzed such metrics as the percent of GDP that a country spends on defense and procurement of major new equipment (including research and development), the percent of allied forces that are deployable, the percent of allied forces that are sustainable, and contributions to NATO Command Structure positions. While valuable, these metrics do not provide a good indication of whether countries will be able to perform specific military missions. Most do not translate defense spending or military capabilities into whether and how countries will be able to perform on the battlefield.

Assessing military performance is a complex undertaking. How a state — or states — perform in conducting military missions can include a wide range of factors, such as strategy, tactics, morale, numerical preponderance, technology, combat motivation, force employment, leadership, and materiel. Other factors are also important, such as readiness, sustainability, modernization, and force structure. In fact, NATO countries spend an average of 40 percent of their defense budgets on personnel costs, with an emphasis on recruiting and retaining an all-volunteer force. Some countries, such as Spain and Italy, spend roughly 60 percent on personnel. These estimates do not include equipping and fielding the fighting force, which leads to inaccurate or incomplete metrics on how well an individual NATO member state may perform on any given military mission.

To complicate matters, military forces frequently perform a wide range of missions, such as countering terrorists, deterring aggressors, conducting peace-keeping efforts, enforcing sanctions, performing freedom of navigation missions, and training foreign police and soldiers. Proficiency in one or several missions does not indicate proficiency in all or even most missions.

To better understand military missions, this chapter divides missions into three categories: small-scale missions; medium-scale missions; and large-scale combat. These categories can be differentiated by their scale and scope. Small-scale missions, for example, are at one end of the conflict continuum and generally include limited or no combat. Large-scale combat sits at the other end of the conflict continuum and can involve joint, multi-domain operations involving the air, ground, maritime, cyber, and space domains. Figure 4.1 provides an overview of the types of military missions and examples of current and historical operations involving European countries.

First, small-scale missions sit at one end of the conflict continuum. They include such activities as noncombatant evacuation operations (NEOs), peace-keeping, and foreign humanitarian assistance efforts. NEOs involve situations in which military forces attempt to evacuate noncombatants from foreign countries when their lives are endangered by war, civil unrest, or natural disaster.

Peacekeeping consists of military support to diplomatic, economic, or other efforts to establish or maintain peace in areas of potential or actual conflict — often to support such regional or international institutions as the United Nations or African Union. As highlighted in Figure 4.1, historical examples involving European countries include Operation Concordia and Operation Allied Harmony in the former Yugoslav Republic of Macedonia, Operation Althea in Bosnia and Herzegovina, and numerous operations in support of UN peacekeeping efforts across the globe.

Finally, humanitarian assistance involves the use of military forces to reduce human suffering, pandemics, disease, or hunger. Examples of foreign humanitarian assistance include the European Union Force Chad and Central African Republic and NATO’s humanitarian relief efforts in Pakistan following the October 2005 earthquake, which killed an estimated 53,000 people.

Second, medium-scale missions include a wide range of activities to establish, shape, and maintain relations with other nations. The general objective is to protect national interests by building or maintaining support to partner nations, enhancing their capability to provide security and maintain stability, and establishing operational access. Security cooperation involves military interactions with foreign security agencies to build or maintain defense relationships, develop their capabilities, and provide access.

Crisis management missions include efforts to conduct expeditionary air, land, and maritime deployments. Many of these specific operations — such as Operation Allied Force, Operation Deliberate Force, and Operation Unified Protector — involve multiservice military deployments that require several thousand personnel. NATO’s Operation Unified Protector, for instance, had three components: the enforcement of an arms embargo in the Mediterranean, the enforcement of a no-fly zone to prevent aircraft from bombing civilian targets, and air and naval strikes against those military forces involved in attacks or threats to attack Libyan civilians and civilian-populated areas.

These types of activities can also involve deterrence (which includes actions to persuade an adversary not to initiate a war or other military activity because the expected costs and risks outweigh the anticipated benefits) and assurance (which includes actions to support an ally or partner’s government and population and communicate a credible message of confidence in the dependability of its security commitment). Assurance measures might involve flying airborne warning and control systems (AWACS), deploying Patriot air defense systems, conducting enhanced air policing, deploying a ship or a maritme strike group off a threatened country’s coast, rotating high-readiness forces into a particular country or region, and utilizing surface-to-air, medium-range platform terrain (SAMP/T) systems. NATO created the tailored Forward Presence in 2016 to help reassure Bulgaria and Romania and establish a Black Sea presence.

▲ Figure 4.1: Types of Military Missions. Source: CSIS.

Third, large-scale combat sits at the other end of the conflict spectrum from crisis response. Large-scale combat involves a series of tactical actions — such as battles — conducted by combat forces to achieve strategic or operational objectives. It can include a range of activities, from wars in specific countries or regions involving a combination of multidomain air, ground, maritime, and other capabilities, to world wars among great powers. These types of missions generally require substantial power-projection capabilities, including the ability to deploy and employ military forces rapidly over long distances and for sustained periods. Historical examples involving European countries include Operation Enduring Freedom and Operation Iraqi Freedom, as highlighted in Figure 4.1.

ASSESSMENT OF EUROPEAN CAPABILITIES

This section applies the framework outlined in Figure 4.1 to analyze European capabilities to perform specific missions. It provides a qualitative judgment of European capabilities through 2030 — especially from major powers such as France, the United Kingdom, and Germany — based on the results and analyses from wargames, scenarios, exercises, after-action reviews, and other analyses. The goal is to provide reasonable estimates of whether European states may be able to conduct future missions across the continuum of conflict in four regions: Europe (including the Mediterranean), the Middle East, Africa (especially North, West, and East Africa), and the Indo-Pacific. These are the regions where European forces are most likely to deploy in the future, based on future planning considerations and past actions.

The assessment is based on whether the evidence from wargames and other analyses suggests that European states can successfully conduct the designated mission with no, limited, or significant U.S. support. In Figure 4.2, “High” (or green) means that the major European states — such as the United Kingdom, France, and Germany — generally have the capability to successfully conduct the designated type of mission in the identified region without U.S. aid. A “high” judgment is not a fact or a certainty, however, and such judgments still carry a risk of being wrong. “Medium” (or yellow) means that major European states have the capability to successfully conduct the designated type of mission in the identified region with moderate U.S. aid, such as transport, aerial refueling, or ISR capabilities. “Low” (or red) means that major European states have the capability to successfully conduct the designated mission in the identified region only with significant U.S. aid. Figure 4.2 provides a summary of the main findings.

Small-Scale Missions: Major European states have a high likelihood of performing most small-scale missions through at least 2030 with limited U.S. aid or, in some cases, with none at all. NATO 2030 provides a set of targets that individual allies and the broader NATO alliance are expected to meet. Europe’s ability to perform critical missions is especially high in Europe, the Middle East, and parts of East, West, and North Africa, though there may still be challenges in some areas.

First, European states may face difficulties conducting some missions in Asia and parts of Africa because of limited posture (especially bases), few enablers (such as airlift, aerial refueling, maritime logistics, command and control, and ISR), and a large geographic area. These factors could also impact the speed that European militaries could respond to contingency missions because of the small number of European personnel in the region and a vast geographic area. Germany, for instance, already faces airlift, combat search and rescue, and other limitations that will complicate noncombatant evacuation and other missions in Asia or parts of Africa. Although German chancellor Olaf Scholz announced a €100 billion ($106 billion) special fund for Bundeswehr development — including a heavy focus on air capabilities — shortly after Russia’s February 2022 invasion of Ukraine, the allocation will primarily finance existing military plans that had been unfunded or underfunded rather than support new developments.

Second, the deployment of Russian and Chinese assets — including intelligence, electronic warfare, and anti-aircraft weapons systems — could complicate missions in Africa, the Middle East, and Asia. Russia has expanded its military presence in the Middle East and Africa, particularly in countries such as Syria and Libya. China continues to build military and civilian infrastructure in countries such as Djibouti, where France has a significant military presence, and Chinese private security companies such as China Security Technology Group (中国安保技术集团), Hua Xin Zhong An (Beijing) Security Service (HXZA) (华信中安集团), and Zhongjun Junhong (中军军弘安保集团) conduct armed maritime escort and other security services in strategic waterways in Africa and the Middle East.

In addition, growing competition could lead Moscow and Beijing to pressure some host-nation countries in these regions to limit or reject U.S. and European militaries from using their air bases or ports or to deny overflight access. During the Cold War, for example, the Soviet Union routinely pressured foreign countries to refuse U.S. basing rights and overflight permission for operations that Moscow opposed. Already, Russia has helped to dislodge French, EU, and UN missions in countries such as Mali, including through the use of private military companies and other quasi-independent proxies. Russia is unlikely to replicate this approach widely outside of states with weak governance and autocratic leadership, but China may prove more capable in this regard. By 2030, China’s People’s Liberation Army (PLA) probably will be able to deploy and sustain military forces across Asia and much of Africa, and will likely maintain a lower level of power-projection capabilities in areas with key Chinese economic interests, such as Latin America and the Middle East. Chinese competence may include military airlift and sealift capabilities, and its efforts to expand overseas basing and logistics infrastructure may enable the intelligence, logistics, and communications support needed to deal with threats to China or to disrupt its adversaries’ global operations. China may also have the ability and posture to deploy aircraft carrier strike groups to the Indian and Pacific Oceans by 2030.

▲ Figure 4.2: Overview of European Capabilities to Perform Missions. Note: CSIS.

Medium-Scale Missions: Europe’s largest militaries will likely be able to perform numerous medium-scale missions through 2030 with limited U.S. assistance — especially in Europe and the Middle East — and potentially beyond 2030 with enhanced capabilities as a result of NATO’s 2030 plan. For example, European militaries will be able to conduct numerous deterrence missions in Europe. Similarly, European militaries likely will be able to conduct most assurance missions to support governments and their populations, such as flying AWACS, conducting enhanced air policing, and deploying SAMP/T systems.

France is likely to retain sufficient capabilities to conduct many of these missions in Europe, the Middle East, and possibly West Africa. France has undertaken medium-footprint expeditionary interventions, such as the 4,000-troop mission to defeat Islamist militants in Mali in 2013 to 2014. In recent years, however, France has experienced diplomatic setbacks in West Africa that may limit its ability to operate in the region, including the termination of Operation Barkhane in Mali and deteriorating relationships with other West African states. Nonetheless, through 2030, France will likely retain a sustained capability to conduct unilateral and joint expeditionary operations, especially as it resolves its shortfalls in aerial refueling, strategic and tactical airlift, unmanned aircraft systems, and precision-guided munitions. In addition, the French navy will likely remain capable of performing freedom of navigation, counterpiracy, counter smuggling, counternarcotics, and presence patrols — especially in such areas as the Mediterranean Sea, North Atlantic, Red Sea, and Arctic Ocean.

Similarly, the United Kingdom will likely be able to perform many of these medium-scale missions through 2030 in Europe, the Middle East, and parts of Africa. But the United Kingdom will likely have significant limitations operating in the Indo-Pacific, where there are at least 1.7 million UK citizens. The United Kingdom is attempting to expand its presence and activity and conduct such missions as freedom of navigation and maritime patrol. The United Kingdom has conducted some exercises in the Indo-Pacific — including with Australia, Malaysia, Singapore, and New Zealand — to enable it to play at least a limited role. In addition, the United Kingdom is developing a fifth-generation carrier strike group and investing in some next-generation capabilities, such as directed energy weapons and swarming drones.

More broadly, European states will likely retain sufficient capabilities to perform several of these missions. France, the United Kingdom, and several other European countries — such as Germany — maintain competent special operations forces, allowing them to conduct security force assistance, counterterrorism, and other types of missions. In addition, Europe has several competent law enforcement and paramilitary forces — such as France’s Gendarmerie and Italy’s Carabinieri — capable of security force assistance, including training and advising foreign security forces. Several European states — such as France, Germany, the Netherlands, and the United Kingdom — will also likely retain significant capabilites to conduct offensive and defensive cyber operations, including against higher-end threats such as Russia and China. Despite these capabilities, some European states may be hesitant to integrate offensive cyber capabilities into multilateral operations because of national sensitivities. European countries are also improving their ability to build computer network resilience, cyber institutions, and response strategies, which will likely improve their ability to engage in offensive and defensive cyber missions. Finally, European countries will also likely have sufficient capabilities to conduct deterrence and assurance missions, such as enhanced air policing, maritime patrol aircraft, and forward-deployed troops.

European states may face several types of challenges, based on a review of wargames and other analyses. First, they will likely face some problems in the Indo-Pacific region and parts of Africa with conducting military engagement, security cooperation, and similar types of missions without help from the United States and other partners. France has some bases in New Caledonia, French Polynesia, Mayotte, Réunion, Djibouti, and the United Arab Emirates. The United Kingdom likewise has overseas bases in Brunei and Diego Garcia. Still, European militaries — even France and the United Kingdom — lack sufficient basing, airlift, logistics, aerial refueling, and power-projection capabilities in the Indo-Pacific region.

Second, if planned new investments are not realized, air and naval patrol missions could become challenging even within Europe. Personnel shortages, low aircraft-readiness rates, and some allies’ lack of investment in integrated air and missile defense capabilities will likely inhibit future missions. Staff air patrol shortfalls, for example, have impacted missions in some areas such as the Black Sea. Fortunately, several allies are currently investing in ground-based air defense, short-range air defense, new fighter jets, and long-range patrol assets that will be in service by 2030.

Similarly, if current defense plans are not realized, some types of maritime patrol missions could be impacted by shortages in frigates, problems with information sharing, and limited specialized capabilities such as anti-submarine warfare (ASW). Operation Sea Guardian, which occurred in the Mediterranean, was chronically underresourced and faced particularly acute shortfalls in such areas as naval vessels (including surface combatants) and maritime patrol aircraft. The German navy, for example, will likely continue to face personnel shortages, maintenance delays, spare part shortfalls, and procurement challenges. The major allies recognize these deficencies and are investing significantly in frigates and other ASW platforms that will enter service by 2030, if not sooner. Nevertheless, challenges may remain acute in the Indo-Pacific region, with such significant distances to cover in the Indian and Pacific Oceans.

Third, shortfalls could impact some types of security force assistance missions, especially in countries that face high levels of terrorism and insurgency and present a non-permissive environment. In the NATO Training Mission Iraq, there were shortfalls in filling Mobile Training Teams as well as force protection concerns. The NATO mission in Kosovo, called Kosovo Force, faced personnel and intelligence shortfalls, including in human and signals intelligence.

Large-Scale Combat: European states are likely to face significant challenges conducting large-scale combat missions, particularly in such areas as heavy maneuver forces, naval combatants, and support capabilities such as logistics and fire support. While much of this section focuses on European challenges in conducting large-scale combat involving Russia, China, or Iran, there are some broader problems that may impact large-scale combat. For example, while NATO 2030 lays out an ambitious agenda for all member states to improve their national capabilties, it is unclear whether European states will realize planned major improvements in the interoperability of their forces regarding the usability of land maneuver formations; suppression of enemy air defense; electronic warfare; chemical, biological, radiological, and nuclear defense; and medical support to operations. It is also unlikely that European militaries will be able to operate at scale in high-end scenarios against countries such as Russia and China without significant U.S. assistance.

In addition, challenges in the land and maritime domains will likely impact Europe’s ability to successfully perform high-end missions. While there may be new main battle tanks, infantry fighting vehicles, and armored personnel carriers, it is unclear if European militaries will adequately fix problems in combat support and training or address widespread shortfalls in materiel stockpiles by 2030. Significant numbers of infantry battalions are likely to lack their required combat capabilities over the next decade, half of all combat brigades may lack short-range air defense, and roughly one-quarter of infantry divisions may lack long-range indirect fire capabilities. Maritime capabilities also pose a challenge for large-scale combat, including a qualitative shortfall in sensors (including sub-surface sensors), weapons, force protection, and survivability systems.

Despite these challenges, European militaries are improving their capabilities in some areas. For example, European combat air capabilities will likely improve, with the shift to fifth-generation combat aircraft and improvement in air-to-air refueling, transport, and cargo capabilities because of the multinational Multi Role Tanker Transport aircraft fleet. Members of the F-35 consortium — such as Denmark, Italy, the Netherlands, Norway, and the United Kingdom — are transitioning their fourth-generation F-16 fighters to fifth-generation F-35s. Several aspects of the F-35s, such as stealth and data-sharing capabilities, will be particularly helpful in conducting large-scale combat missions. Several other European countries, such as Belgium, Finland, Germany, Poland, and Switzerland, are also procuring and operating F-35s. The United Kingdom, along with Italy and Sweden, is developing a sixth-generation future combat aircraft, the Tempest, which is expected to enter service in the mid-2030s. Furthermore, the reevaluation of defense priorities after Russia’s 2022 invasion of Ukraine and efforts to supply materiel to Ukraine have accelerated the modernization of equipment and ammunition stocks, particularly in Central and Eastern Europe.

The Russian invasion has also motivated a European Commission review of the EU defense industrial base and a range of new initiatives to increase weapons and munitions stocks, modernize equipment, invest in research and development, and increase cooperation between EU member states. In October 2023, for example, the Council of the European Union approved the European Defence Industry Reinforcement through Common Procurement Act, a €300 million ($318 million) instrument that directly incentivizes collaborative defense procurement. Such efforts aim to reduce fragmentation in EU defense capabilities and planning and to strengthen the European defense industrial base, but their ability to impact large-scale European capabilities through 2030 will require sustained support and significantly increased resourcing. European countries will likely continue to develop substantial space-based capabilities that will facilitate their participation in large-scale combat. For example, France has committed to increasing its military space budget to improve its space and counterspace capabilities, including active defense for space objects. The United Kingdom is also attempting to augment its satellite communications capability, Skynet, and develop opportunies for utilizing or enhancing quantum field sensors; space-based ISR with multi-sensor capabilities; additional payloads for Skynet; and new options to exploit electromagnetic targets.

HIGH-END CHALLENGES

This section highlights several scenarios that help examine Europe’s ability to effectively perform high-end military missions: a war with Russia in the Baltics, a war with Iran in the Persian Gulf, and wars with China in the Taiwan Strait or South China Sea. These cases represent plausible future scenarios involving large-scale combat and have been important as part of U.S. Operation Plans (OPLANS). This section uses the results and analyses from wargames, scenarios, exercises, and other analyses to assess the ability of European states to perform military missions through 2030.

War with Russia: The results of wargames, scenarios, and other analyses of a war with Russia in the Baltics indicate some challenges with a war in Eastern Europe, even with current Russian weaknesses. As outlined in Chapter 3, these challenges could increase if Russia is able to rebuild its military capabilities over the next decade with help from China and other countries, and if European countries are slow to build their capabilities or fail to learn from the war in Ukraine, including in their efforts to re-strategize, modernize forces, and increase complementarity in research, development, and procurement.

Wargames and other analyses show a major disparity in long-range fires between Europe and Russia even with projected European investments in such systems. European forces will likely continue to be susceptible to fire throughout the theater from Russian systems and lack sufficient ground-based air defense capabilities to counter Russian cruise and ballistic missiles. These problems could be compounded by Russian long-range integrated air defense systems (IADS), which can prevent European states from using airpower in a decisive way early in a conflict. Russian rockets and artillery may also outrange their European counterparts and threaten ground forces.

There are also significant challenges with the number, quality, and capabilities of most European ground forces. While Germany’s current defense plan aims to have three combat-capable divisions by the end of the decade, reaching this milestone is unlikely because the German army is shrinking. The United Kingdom has also cut the size of its army and plans to rely more heavily on reserve forces to make up the delta.

Other European capability gaps that could impact operations include: a longer-range, fast-flying radar-homing missile for suppressing modern surface-to-air missile (SAM) systems; mobile short-range air defense systems; Long Range Anti-Ship Missiles (LRASMs); and area munitions for the Multiple Launch Rocket System (MLRS)/Army Tactical Missile System (ATACMS). These problems would be particularly serious without U.S. involvement, though allies’ investments in some of these systems could help them hold initial ground. These include acquisitions of ATACMS and Patriots by Poland and Hungary, the National/Norwegian Advanced Surface to Air Missile System (NASAMS) by Lithuania, and the High-Mobility Artillery Rocket System (HIMARS) by Poland. German and other European forces might also face significant challenges neutralizing the Bastion-P coastal defense cruise missile systems located in Kaliningrad and could face sigificant command and control problems.

Iranian Missile Threat: European states will likely face significant challenges dealing with a missile threat from Iran, based on a review of wargames, scenarios, and other analyses. Under the oversight of the Islamic Revolutionary Guard Corps Aerospace Forces Al Ghadir Missile Command, Iran will likely focus on fielding more accurate and longer-range missiles over the next decade that include counter-measures for defeating U.S. and partner missile defense systems. Iran will likely continue to expand its missile ranges through 2030. A ballistic missile based on Iran’s Zoljanah space launch vehicle could carry a one-ton warhead as far as 5,000 kilometers, allowing Iran to strike every European capital. These developments will supplement other Iranian missiles, such as the Shahab-3 and Khorramshahr medium-range ballistic missiles, which have have an operational range of up to 2,000 kilometers. Iran also has layered area denial and anti-surface warfare capabilities, including naval mining (e.g., moored contact, drifting contact, and limpet mines), small boat swarming tactics, and coastal defenses.

European missile defense capabilities are lagging. Figure 4.3 outlines EU and NATO multinational air and missile defense projects, many of which will not be fully operational until 2030 or later. For example, NATO’s Ballistic Missile Defense (BMD) program — which is designed to protect European populations from a ballistic missile attack from a country such as Iran — likely will not achieve full operational capabilities until at least 2030. France possesses one SAMP/T ground-based air defense missile squadron that will be updated by 2025. Spain is expected to have two long-range radars by 2024. Most of the European countries developing sea-based, lower-layer ballistic missile defense are forecasting delays — including to the development of a suitable interceptor missile — through the end of the decade. The U.S. contribution to NATO’s BMD architecture will remain critical, including the Aegis Ashore and periodic rotation of the Terminal High Altitude Aerial Defense (THAAD) missile defense system.

▲ Figure 4.3: EU and NATO Multinational Air and Missile Defense Initiatives. Source: Sean Monaghan and John Christianson, Making the Most of the European Sky Shield Initiative (Washington, DC: CSIS, 2023), 8.

Most scenarios involving an Iranian missile threat in the Persian Gulf suggest that European countries will be able to play at best a limited role. Forces from several allied nations — particularly air, naval, and long-range fires forces from Israel, Kuwait, Saudi Arabia, Qatar, and the United Arab Emirates — might participate alongside the United States. Kuwait, Saudi Arabia, Qatar, the United Arab Emirates, and Oman could each potentially commit one or more combat squadrons (and Saudi Arabia one or more wings) to a conflict. Some Middle Eastern countries possess the HIMARS with ATACMS and could conduct fires across the Persian Gulf against Iranian targets. European allies, such as the United Kingdom and France, could commit some naval and air forces and possibly forward station assets at their bases in the region. But their missile defense capabilities are limited. Barring extended warning of potential Iranian aggression, and without substantial airlift assets, it is unlikely that European forces would be available during the critical early days of a Persian Gulf conflict.

War with China in the Taiwan Strait or South China Sea: European states will likely lack the capability by 2030 to successfully conduct large-scale combat operations against China, including in the South China Sea or Taiwan Strait. The challenges in Asia are significant — even for the United States, which has likely lost “overmatch” with China. The Chinese Communist Party’s 14th Five Year Plan, which goes through 2025, calls for accelerated development of military mechanization, informatization, and intelligentization. China is focusing on military applications for such areas as artificial intelligence, autonomous systems, biotechnology, information technology, quantum computing, robotics, advanced materials and manufacturing, and deep-sea technologies.

Much of China’s activity has focused on the development or acquisition of power-projection capabilities — from fifth-generation aircraft to China’s third aircraft carrier — designed to give China greater ability to influence actions in the Indo-Pacific. The PLA increasingly has the ability to put aircraft carrier strike groups at risk and neutralize ground-based air-power. By 2030, the PLA will likely have the capability to deny operations within the First Island Chain and to complicate operations within the Second Island Chain. By 2030, the PLA may increasingly advance and integrate joint capabilities across multiple domains, which will improve China’s strike capabilities, extend the range and efficacy of force projection, and protect China’s interests.

China is developing the J-20A and J-20B fifth-generation stealth fighters, armed stealth unmanned aircraft systems, the DF-17 medium-range ballistic missile that carries an advanced hypersonic glide vehicle, and the J-31 medium-weight stealth fighter. China is also developing kinetic kill vehicle technology to field an upper-tier ballistic missile interceptor by 2030; longer-range, more accurate, and increasingly lethal ballistic and cruise missiles, including conventionally armed intercontinental-range missile systems; air defenses; and other platforms and systems. China also continues to expand its development and modernization efforts of unmanned aircraft systems, including next-generation capabilities such as air-to-air and air-to-ground combat and swarming capabilities.

The People’s Liberation Army Navy (PLAN) is fielding new carrier-based aircraft, as well as ASW, helicopters, unmanned aircraft, land-based maritime strike, and air defense forces. China may have as many as five aircraft carriers by 2030, aided by helicopter carriers and a fleet of destroyers. The overall PLAN battle force will likely comprise 435 ships by 2030. China has developed a credible and increasingly robust over-the-horizon ISR capability. The development of China’s space, counterspace, and electronics sectors has enabled it to increase the pace of satellite launches and deploy a wider range of sophisticated ISR satellites. China’s development of anti-ship ballistic missiles presents a heightened maritime threat. At the same time, the ongoing modernization of Chinese air and submarine capabilities represents a more challenging threat to carrier strike groups. Some modeling suggests that the effectiveness of the Chinese submarine fleet (as measured by the number of attack opportunities it might achieve against carriers) has risen significantly over the past 25 years. Chinese submarines would present a credible threat to surface ships in a conflict over Taiwan or the South China Sea. The PLAN’s total submarine force is expected to number 65 by 2025 and 80 by 2035.

▲ Figure 4.4: China’s Regional Missile Threats: Fielded Nuclear Ballistic Missiles. Source: Office of the Secretary of Defense, Military and Security Developments Involving the People’s Republic of China (Washington: U.S. Department of Defense, 2023), 68.

Based on these developments, European militaries will not likely have the power-projection architecture and capabilities to play a major role in large-scale combat against China. They lack significantly deployable capabilities in such areas as ASW; ISR; ballistic missile defense; air precision strike; expeditionary logistics; and suppression of enemy air defense — and would likely prioritize the capabilties they do have for a Europe-based fight. Although NATO’s 2022 Strategic Concept identified China’s political ambitions and coercive activities as a challenge for the first time, the document emphasized the Chinese threat to Euro-Atlantic security — indicating that the development of capabilities in the Indo-Pacific is not currently an alliance priority. With the exception of France, which has military assets and some 7,000 to 8,000 troops permanently stationed in the region, European countries lack the significant posture and prepositioned forces in the Indo-Pacific region needed to move quickly in the early stages of any conflict. The huge distances in the Indo-Pacific will also stress European allies’ air-to-air refueling and transport capabilities. Nevertheless, European states can provide some capabilities — such as cyber and space — to support the United States or other countries in the region, including Australia, South Korea, Japan, and New Zealand, and contribute to lower-end deterrence and assurance missions.

CONCLUSION

The goal of this chapter was to focus on military missions and to move beyond assessing whether European countries will be able to increase their defense spending to 2 percent of GDP or fix capability gaps. In examining which types of missions European militaries will be able to effectively perform in Europe, the Middle East, parts of Africa, and the Indo-Pacific, this analysis highlights several findings.

To begin with, European reliance on the United States can be divided into several tiers, as illustrated below. These tiers represent a judgment about whether European states could operate independently of the U.S. military, not whether they should. They include:

• Tier 1 Missions: Low Reliance on the United States: Most European states likely will not require aid from the United States for such missions as noncombatant evacuation, peackeeping, foreign humanitarian assistance, counternarcotics, counterterrorism, security force assistance, counter illegal migration, air patrol, and maritime patrol missions — particularly in and around Europe.

• Tier 2 Missions: Medium Reliance on the United States: Most European states likely will require some aid from the United States for military engagement, security cooperation, deterrence, and assurance missions in parts of the Middle East and Africa. In these regions, most European militaries could face some challenges with airlift, aerial refueling, basing, and other issues over extensive geographic areas.

• Tier 3 Missions: High Reliance on the United States: Most European states likely will require significant aid from the United States for large-scale combat, particularly with Russia and China. In addition, European militaries likely will also require U.S. aid to effectively perform numerous missions (such as deterrence and assurance) in the Indo-Pacific.

In addition, some European states — particularly larger powers such as the United Kingdom and France — will likely have the capability to conduct most types of missions at the lower end of the conflict continuum without U.S. military aid. Examples include noncombatant evacuations, peacekeeping, and foreign humanitarian assistance.

Major European states will also likely be able to conduct most types of medium-scale missions, such as security force assistance, counternarcotics, counterterrorism, and air and maritime patrol. European militaries may face resource issues, including shortfalls in the number of aircraft, naval vessels, personnel, or spare parts, which could stress their ability to fill several missions concurrently or for an extended duration. Nevertheless, they likely will not have significant capability gaps in accomplishing most of these missions, particularly in Europe.

However, European militaries — including the United Kingdom and France — will likely struggle to conduct large-scale combat, where European states still lack sufficient heavy maneuver forces, airlift, naval combatants, and support capabilities, such as logistics and fire support. Although European allies and partners of the United States plan to improve these capabilities by 2030 as part of a greater NATO-agreed initiative, it is unclear whether they will be successful. European challenges may be particularly notable with large-scale, high-end conflict at short notice given most European countries’ persistent readiness challenges. Another challenge will likely be missions in the Indo-Pacific, where European maritime and air forces lack sufficient airlift, aerial refueling, and basing to sustain operations. Countries such as France and the United Kingdom could mitigate basing challenges by reaching agreements with some countries in the region. As highlighted later in Chapter 6, these are areas on which the United States can focus as part of security cooperation and industrial base cooperation with European allies and partners.

As noted earlier in this chapter, Germany and the United Kingdom may struggle to field some units because of manpower shortages. The shrinking forces of both countries reflect an overall trend affecting not only Europe but also the United States and Canada in trying to recruit and retain an all-volunteer, professional armed force. This is a challenge that needs to be addressed by all Western nations. Without adequate active-duty volunteers, many national leaders will need to consider whether a greater reliance on reservists will be needed to meet force goals and operational requirements. Additionally, consideration may need to be given to reinstitute conscription in some form to have a minimally trained reserve force capable of being called up and deployed if needed.

There are also a range of factors that could impact the outcome of European missions, such as political will, financial constraints, and variation in threat perception. While all members have pledged to honor NATO’s Article V commitment, many allies in Western and Southern Europe have a significantly different perception of the Russian threat than those nations of Northern and Eastern Europe. Conversely, nations in Northern and Eastern Europe have a different threat perception of illegal migration and terrorist flows than those in Southern and Western Europe. Although the overall strategic focus in Europe has shifted toward the northeast following the Russian invasion of Ukraine, effective development of allied capabilities and strategy will require a balanced threat assessment. Ensuring that all allies share a common risk assessment and understanding that the alliance, as a whole, needs a wide spectrum of deep capabilities to address these threats is what NATO 2030 was designed to achieve and what allied leaders reaffirmed at the Madrid summit in June 2022.

Recruitment, training, operations and maintenance, and purchasing of spare parts will also be key factors in assessing whether NATO allies — including the United States — can meet the 2030 goals and be able to maintain them post-2030. If NATO leaders can find the political will to ensure its 2021 Brussels and 2022 Madrid declarations are not hollow, then many of the missions outlined above can be achieved and many of the present identified gaps can be filled. However, if there is not ample political support — as well as adequate funding — to do what is needed to meet 2030 objectives, many of the challenges noted in this chapter may become even more difficult.

FORWARD DEFENSE

CH. 05

U.S. INTERESTS AND DEFENSE OBJECTIVES

This chapter examines U.S. interests and objectives in Europe in the context of U.S. military posture. It asks several questions. What are U.S. interests in Europe? In light of these interests, what should be the United States’ major defense objectives and capabilities in Europe? Based on the analysis, this chapter makes three main arguments.

First, the United States has several enduring interests in Europe: protect the U.S. homeland and the security of the American people; promote and expand economic prosperity and opportunity; realize and defend the democratic values at the heart of the American way of life; and defend and support the United States’ European allies and partners. Second, the United States has several defense objectives that flow from these interests, such as deterring and defeating conventional and nuclear-armed conflict directed against the U.S. homeland and NATO allies. Third, deterrence should be the conceptual lynchpin of U.S. posture in Europe, including a combination of deterrence by punishment (for areas of NATO’s eastern flank) and deterrence by denial (for much of the rest of Europe). Nevertheless, deterrence is likely to be more difficult below the threshold of conventional war for Russian gray zone activities and irregular warfare.

The rest of this chapter is divided into five sections. The first outlines U.S. interests in Europe. The second section examines U.S. defense objectives, which flow from U.S. interests. The third explores deterrence. The fourth section examines several operational concepts. The fifth section analyzes risks to U.S. posture in Europe.

U.S. INTERESTS

The United States has several broad security interests in Europe today, which will likely persist over the next decade:

• Protect the U.S. homeland and the security of the American people, including from threats emanating from Europe;

• Promote and expand U.S. economic prosperity and opportunity;

• Realize and defend the democratic values at the heart of the American way of life; and

• Defend and support the United States’ European allies and partners.

The United States has interests elsewhere in the world. In particular, China will likely be the United States’ main global competitor. China poses a challenge to the United States around the globe because of its expanding conventional and nuclear capabilities, irregular warfare and gray zone activities, technological and economic competitiveness, and “wolf warrior” diplomacy. The United States has other important interests in other regions, including in the Middle East, Asia, Africa, and Latin America.

But it is a false dichotomy to argue that the United States needs to choose between these interests — especially between China and Russia. Both are authoritarian regimes cooperating on two major axes. Beijing and Moscow have deepened their military, economic, and diplomatic ties since Russia’s invasion of Ukraine. The United States should develop a two-front strategy that works with allies and partners to counter China and Russia. U.S. interests in Europe are significant, and U.S. allies and partners in Europe share the United States’ democratic values and account for significant military, economic, and technological power. Examples include:

• Democracy: Europe accounts for the largest number of democratic countries of any continent in the world. Europe’s commitment to freedom and democracy is particularly critical because of 16 straight years of democratic decline worldwide due to the global expansion of authoritarian regimes, including China, Russia, and Iran.

• Military Power: European countries have 4 of the 10 largest defense budgets in the world.

• Economic Power: Europe includes 3 of the 10 largest economies in the world, as measured by purchasing power parity. Combined, the European Union has the third-largest economy in the world.

• Population: The population of the entire European Union is 447.7 million, which would make it the third-largest country in the world.

Public support for NATO in the United States has been over 70 percent for the past two decades. In 2022, at least three-quarters of Republicans, Democrats, and independents believed that the United States should maintain or increase its support to NATO, according to a Chicago Council on Global Affairs poll. In 2023, U.S. support for NATO remained high, though some Republicans and independents were more likely to focus on domestic issues. Still, a significant 91 percent of Americans — including Republicans and Democrats — had unfavorable views of Russia in 2023.

Since its establishment in the 1949 Washington Treaty, NATO has been the lynchpin of U.S. security in Europe. The bedrock of NATO is a collective defense provision — an attack on one is an attack on all — that was codified in Article V of the Washington Treaty. During the Cold War, the alliance served as the primary bulwark against the expansion of the Soviet Union. Following the Soviet Union’s collapse, NATO became the major framework for organizing transatlantic efforts on collective security matters, including military interventions in the Balkans, Afghanistan, and Libya. In addition, several former Soviet republics (such as Latvia, Lithuania, and Estonia) and members of the Soviet-aligned Warsaw Pact (such as Poland, Hungary, the Czech Republic, Bulgaria, Romania, and Slovakia) became NATO members.

These treaty relationships have benefited the United States for several reasons. One is supporting U.S. leadership. As a result of the United States’ central role in transatlantic and international relations that NATO has in many ways cemented, Americans have enjoyed unprecedented economic prosperity and freedom. Successive American governments have been afforded both de facto and de jure privileged status related to such issues as trade partnerships and access to bases in large part because of the outsized role that the country plays in the defense of its allies. For example, the United States would not have been able to prosecute expeditionary and counterterrorism operations in the Middle East and Africa were it not for the bases and prepositioned equipment that the United States has been able to maintain on allied soil in Europe.

Another long-standing reason for U.S. engagement in Europe is to enable U.S. strategic depth. The United States’ geographic location, protected by the Atlantic and Pacific Oceans, no longer provides the same security as in previous decades because of advances in long-range strike, cyber operations, space, and other technological developments. As a result, it is prudent to station U.S. forces overseas to contend with adversary aggression — if not outright conflict — far from the U.S. homeland. Not only does this make the U.S. homeland less vulnerable to outright war, but forward presence is also relatively cost effective.

Finally, the NATO alliance today affords the United States strategic flexibility. Most of the United States’ main security challenges — from China and Russia to Iran and terrorism — cannot be tackled by one state alone, not even the United States. Allies are critical. They enable flexible cooperation and consultation on any number of strategic issues as they arise. In short, the United States has significant interests in Europe that will likely persist over the next decade.

DEFENSE OBJECTIVES

Based on these interests, the United States has several defense objectives in Europe:

• Deter and defeat conventional and nuclear-armed conflict directed against the U.S. homeland and U.S. allies, as well as coerce, persuade, and influence adversary behavior;

• Counter irregular and gray zone activities, as well as compete effectively below the threshold of conventional conflict using both defensive and offensive means;

• Counter terrorist and other transnational threats;

• Deter and prevent state and non-state actors from acquiring, proliferating, or using weapons of mass destruction; and

• Maintain access to trade routes and global commons.

A key defense objective should be to deter and defeat conventional and nuclear-armed conflict directed against the U.S. homeland and NATO allies, as well as to coerce, persuade, and influence adversary behavior. This objective includes preventing a country with hegemonic ambitions, such as Russia, from expanding its power through territorial conquest, covert influence, and other means. As Putin explained at length in discussing the historical exploits of Peter I, military expansion was about returning what rightly belonged to Russia:

Peter the Great waged the Great Northern War for 21 years. On the face of it, he was at war with Sweden taking something away from it. . . . He was not taking away anything, he was returning. This is how it was. The areas around Lake Ladoga, where St Petersburg was founded. When he founded the new capital, none of the European countries recognized this territory as part of Russia; everyone recognized it as part of Sweden. However, from time immemorial, the Slavs lived there along with the Finno-Ugric peoples, and this territory was under Russia’s control. The same is true of the western direction, Narva and his first campaigns. Why would he go there? He was returning and reinforcing, that is what he was doing.

This logic is revanchist. Putin went on to highlight the need for expansion today. “Clearly, it fell to our lot to reclaim and strengthen as well. And if we operate on the premise that these basic values constitute the basis of our existence, we will certainly succeed in achieving our goals.” Putin’s desire to expand territorial control is cloaked in the language that the Kremlin is merely acquiring what already belongs to Russia. Putin likely has other countries on his colonial agenda, such as Latvia, Lithuania, and Estonia, which were Soviet republics. Putin’s revanchist aims makes it important to deter and defeat armed aggression.

▲ Figure 5.1: European Underwater Fiber-Optic Cables. Source: “Submarine Cable Map 2022,” Telegeography (CC BY-SA 4.0 DEED); and “How Can We Protect the Internet’s Undersea Cables?,” World Economic Forum, November 4, 2015.

The United States has other defense objectives, such as countering gray zone activities, terrorism, and other transnational threats. For instance, Europe has critical infrastructure that could be threatened by state and non-state activity and pose a threat to the United States. As illustrated in Figure 5.1, one example is the underwater fiber-optic cables that connect Europe with North America and European countries with each other. There are currently 16 cables running under the Atlantic that connect the United States with mainland Europe. They are primarily operated by such companies as Google, Microsoft, France’s Alcatel Submarine Networks, and China’s Huawei Marine Networks. Submarine cables are critical for global communication and account for roughly 95 percent of all transatlantic data traffic. Militaries also use them. These cables are vulnerable to subversion and sabotage by special operations forces and intelligence units; maritime vessels, such as submarines and unmanned underwater vehicles; and possibly non-state actors.

In January 2022, the Russian navy allegedly mapped out the undersea cables off the coast of Ireland and carried out maneuvers, raising serious concerns in Europe and the United States about Russian sabotage. In addition, a Russian government unit allegedly cut an underwater fiber-optic cable off the coast of Svalbard, Norway, in January 2022 in the Arctic Ocean.

Europe’s intricate network of gas and oil pipelines are also vulnerable to sabotage and subversion. In September 2022, for example, there were explosions in the Baltic Sea on the Nord Stream 1 and 2 gas pipelines. Europe is vulnerable to other threats below the threshold of conventional war — such as cyberattacks, misinformation and disinformation, assassinations, terrorist attacks, illegal drugs, human trafficking, and the weaponization of immigrants — from state and non-state actors that may require U.S. defense assistance. In 2021, Belarusian leader Alexander Lukashenko threatened to “flood” the European Union with “drugs and migrants,” and then his government sent thousands of migrants from Iraq and other countries to the borders of Latvia, Lithuania, and Poland in 2021 and 2022.

In addition, the United States will likely need to help deter and prevent state and non-state actors from acquiring, proliferating, or using weapons of mass destruction. On several occasions, Putin has threatened to use nuclear weapons in response to U.S. and other Western aid to Ukraine following the Russian invasion. Russian military leaders also discussed the use of battlefield nuclear weapons in Ukraine, according to U.S. intelligence. The United States could also help track and counter the acquisition — or attempted acquisition — of fissile material and chemical or biological agents or precursors as well as the movement of these materials and their possible use.

A final defense objective is maintaining access to major trade routes and global commons. Europe has some of the most significant trade routes, such as the Dover Strait (between the United Kingdom and France) and the Suez Canal (between the Mediterranean and Red Sea). On March 23, 2021, for example, the cargo ship Ever Given ran aground in the Suez Canal and created a massive backlog of over 400 vessels, significantly disrupting global supply chains, delaying goods from reaching their destinations, and holding up an estimated $9.6 billion of trade each day. U.S. and European maritime vessels — including from the U.S. Sixth Fleet — and aircraft can help to ensure these shipping lanes remain open. As the Arctic ice melts, the Arctic Ocean also represents a major global common with potential shipping lanes.

DETERRENCE

Deterrence should be the lynchpin of U.S. posture in Europe. Deterrence involves preventing an adversary from taking an action that it might otherwise take. There are two types of deterrence relevant to Europe. Deterrence by denial involves preventing an action, such as Russian aggression, by making it infeasible or unlikely to succeed, thus denying a potential aggressor confidence in attaining its objectives. Deterrence by punishment includes preventing an action, such as Russian aggression, by imposing severe costs if an attack occurs. Some have referred to this as deterrence by cost imposition.

A potential attacker’s fears about the costs of military action, especially when weighed against the benefits, are central to both concepts of deterrence. Costs are often a function of military and civilian casualties, military equipment destroyed or lost, the losses associated with economic sanctions imposed by opponents, trade disrupted, and the expense of mobilizing, deploying, and maintaining forces. In the case of successful deterrence, the attacker might not conduct an action because it believes the probability of success is low and the costs and risks are high. For example, the attacker might assess that it cannot successfully achieve its objectives quickly and with limited costs using a blitzkrieg strategy and would instead face a protracted and bloody war of attrition. As former U.S. secretary of state Dean Acheson noted: “The only deterrence to the imposition of Russian will in Western Europe is the belief that from the outset of any such attempt American power would be employed in stopping it, and if necessary, would inflict on the Soviet Union injury which the Moscow regime would not wish to suffer.”

Deterrence by denial may be achievable for much, though not all, of Europe. A denial strategy requires deploying sufficient numbers and types of conventional forces (such as armored brigade combat teams, fifth-generation aircraft, bombers, artillery, and main battle tanks) and nuclear weapons to prevent the advance of an adversary — such as Russia — on the battlefield. Other factors, such as strategy, are also important. Consequently, for deterrence by denial to be effective in Europe, the United States and its NATO allies need to develop a strategy designed to blunt a Russian blitzkrieg, deploy sufficient numbers of armored brigade combat teams and weapons systems to frontline states in Eastern Europe, and ensure that the defense industrial base of the United States and its allies can produce sufficient munitions and weapons systems for a protracted war.

In some countries, such as the Baltic states and perhaps Finland, deterrence by denial may be difficult. NATO likely lacks a forward posture — including ground forces and capabilities — in some frontline states to prevent a Russian fait accompli. In these cases, the United States and its NATO allies will likely need to credibly signal to Moscow that the costs of a Russian attack would far outweigh the benefits. Examples might include strengthening the ability of U.S. and NATO forces to quickly surge into targeted countries to repel an advance, using — or threatening to use — nuclear weapons, or developing sufficient host-nation capabilities to mount a costly insurgency. In the case of nuclear weapons, deterrence by punishment can sometimes involve an implicit or explicit threat to destroy large portions of an opponent’s industry and other targets. In the case of a potential insurgency, countries such as Switzerland have deterred invasions in part by developing and training local defense units (supported by regular forces) in irregular warfare, prepositioning stockpiles of weapons and equipment to wage a protracted insurgency, and preparing military and civilian units for decentralized and aggressive resistance.

However, deterrence is more difficult below the threshold of conventional war, including for irregular warfare and gray zone activities. Offensive cyberattacks, sabotage, anti-satellite attacks, assassinations, and other types of activities are difficult to deter.

In addition to deterrence, assurance will remain important in Europe. Assurance, which includes land, maritime, and air activities designed to give confidence to allies and partners, can be helpful. Examples might include the stationing of permanent or rotational ground forces and equipment, air and maritime patrols, and military exercises. But assurance is not the same as deterrence, and steps to assure allies and partners do not necessarily deter adversaries. For example, air and maritime patrols may provide some confidence and comfort to host-nation countries near where these patrols occur, but there is little evidence that they deter adversary behavior. Consequently, while assurance steps are important, deterrence should be the conceptual lynchpin of U.S. posture in Europe.

OPERATIONAL CONCEPTS

There are several operational concepts relevant to examining force posture in Europe. One is agile combat employment (ACE), which is designed to increase survivability and generate combat power in the face of an imminent threat or action. The intent is to complicate the adversary’s targeting process, create political and operational dilemmas for the enemy, and create flexibility for U.S. or allied and partner forces. Aircraft are particularly vulnerable if they are postured on bases that are few in number, lack passive defenses (such as shelters and decoys), and lack sufficient active defenses (such as kinetic and non-kinetic interceptors, electronic warfare, and directed-energy weapons) that can help counter air and missile threats.

ACE in Europe involves responding to a rising threat — such as an increase in U.S.-Russian tensions, a Russian military buildup along NATO’s eastern flank, or even a preemptive Russian strike against NATO. ACE might include rapidly moving U.S. and allied aircraft and key personnel, materiel, and logistics from large bases (or main operating bases) to dispersed contingency locations (or forward operating sites) in Europe and perhaps other regions.

One example might involve quickly dispersing aircraft, materiel, and personnel from such main operating bases as Ramstein Air Base in Germany to forward operating sites in Greece, Slovenia, Poland, Romania, or other countries. Rapid dispersal relies on airlift and logistical flows between main operating bases and forward operating sites, ideally covered by air and missile defense. ACE also involves massing and utilizing forces from forward operating sites to potentially strike enemy targets. To be effective, ACE generally requires prepositioning war reserve materiel and building infrastructure at forward operating sites, as well as conducting training and exercises, negotiating access through host-nation agreements, and engaging in other activities with European partners.

In addition, dynamic force employment (DFE) is an operational concept designed to demonstrate operational unpredictability to adversaries, improve deterrence, and support allies. DFE missions might include posturing a guided-missile destroyer to the High North, conducting Bomber Task Force missions, or deploying an F-35 squadron. The idea is to employ forces in ways that demonstrate the United States’ ability to quickly generate combat power and deter adversary action. As the 2018 National Defense Strategy concluded, DFE provides “options for proactive and scalable employment of the Joint Force” and facilitates “combat-credible, flexible theater postures [that] will enhance our ability to compete and provide freedom of maneuver during conflict, providing national decision-makers with better military options.”

The Defender-Europe exercise involved the rapid deployment of air and land capabilities (including Abrams main battle tanks, Bradley Fighting Vehicles, and M113 armored personnel carriers) from the United States and Germany to Drawsko Pomorskie Training Area in Poland. U.S. Army units then conducted company-level, live-fire exercises with Poland’s 17th Mechanized Brigade and 11th Armor Cavalry Division.

However, there are at least three challenges with DFE and deterrence. First, there is little empirical evidence that DFE actually deters adversaries. For example, it is unclear if — and perhaps unlikely that — Russia has been deterred by the occasional deployment of an F-35 squadron, guided-missile destroyer, or Bomber Task Force mission in Europe. To effectively deter, actions need to make an adversary’s activity infeasible or impose severe costs if the activity occurs. DFE likely does neither. Second, DFE may weaken assurance of U.S. allies and partners in cases where permanent or rotational forces are replaced by those engaged in DFE. Third, there is often little or nothing “dynamic” about DFE, since it can sometimes take several months to negotiate with local partners and allow for adversary intelligence collection and warning.

POTENTIAL RISKS

As this chapter argues, the United States has enduring interests in Europe. In particular, Russia presents a long-term threat to the United States and its European allies and partners because of its revanchist intentions and efforts to rebuild its military capabilities. Based on these interests, the United States has several defense objectives in Europe, such as deterring and defeating conventional and nuclear-armed conflict, countering irregular and gray zone activities, countering terrorist and other trans-national threats, deterring and preventing state and non-state actors from acquiring or using weapons of mass destruction, and maintaining access to key trade routes and global commons. To achieve these objectives, the United States needs sufficient land, maritime, air, space, cyber, nuclear, and special operations capabilities in or near Europe.

In addition, deterrence should be the lynchpin of U.S. posture in Europe, and it should include a combination of deterrence by punishment (for areas of NATO’s eastern flank) and deterrence by denial (for most of Europe). But deterrence is likely to be weaker below the threshold of conventional war — including for irregular warfare and gray zone activities, such as cyber operations, disinformation campaigns, sabotage, and subversion. This reality suggests that the United States and its European allies should be aggressive in conducting both defensive and offensive action below the threshold of conventional war.

Nevertheless, any U.S. force posture has risks that need to be managed. Examples include:

• European Military Capabilities: European capabilities remain limited, including for high-end warfare. Particular concerns are such areas as integrated air and missile defense, long-range fires, hypersonics, and sufficient stockpiles of critical munitions, such as for integrated air defense systems and the High Mobility Artillery Rocket System (HIMARS).

• Interoperability: Military interoperability remains a challenge across NATO militaries.

• Political Will: Political will may be fragile in some European countries, including to support U.S. basing, access, and overflight.

• European Defense Industrial Base: The defense industrial bases of most European countries are not adequately prepared for the current security environment. Most have not produced sufficient quantities of the most important munitions and weapons systems — such as long-range fires and integrated air and missile defense systems — for a major war. Most also do not have sufficient surge capacity for a protracted war.

• Escalation: Some posture actions, such as deploying armored brigade combat teams to Finland, could unnecessarily provoke Moscow and risk escalation.

• U.S. Contingencies: Some U.S. forces could be deployed to other regions — such as the Indo-Pacific or Middle East — for contingencies.

• Domestic U.S. Constraints: There are several domestic factors that could impact U.S. force posture in Europe, including the size of the U.S. defense budget or an isolationist turn in U.S. politics.

Based on these risks, U.S. posture in Europe needs to be flexible enough to allow some U.S. forces to surge to other regions — such as the Indo-Pacific or Middle East — in case of contingencies. The next chapter provides more details about U.S. posture.

CH. 06

A FORWARD DEFENSE POSTURE

This chapter outlines recommendations for the future of U.S. military posture in Europe based on the interests, objectives, capabilities, and operational concepts identified in the previous chapter, as well as concerns about Russian military reconstitution and political revanchism. The chapter begins with a discussion of the methodology and assumptions underpinning them, including considerations of the time frame for implementing new U.S. policies, the state of the war in Ukraine and the reconstitution of Russia’s military capabilities, the state of competition with China and the likelihood of a Taiwan conflict, and U.S. global posture writ large.

This chapter also provides recommendations in line with a posture of “forward defense.” It is organized around the categories of ground forces; air combat forces; naval forces; air and missile defense; logistics and enablers; and intelligence, reconnaissance, and surveillance (ISR). The recommendations seek to bolster U.S. ground forces, particularly in NATO’s eastern flank, as a deterrent against Russian military reconstitution and revanchism. In the air and maritime domains, they aim to adopt a flexible posture and work with allies to fill capability gaps in the event of a contingency in the Indo-Pacific or other regions. Finally, they strive to enhance coordination with NATO allies by building partner capacity missions, security assistance, and arms sales to fill capability gaps, improve interoperability, and enhance allied lethality.

METHODOLOGY AND ASSUMPTIONS

The posture recommendations were developed based on the analysis in preceding chapters as well as an evaluation of the U.S. military’s posture both currently and prior to the war in Ukraine. Those postures served as a baseline from which the study team recommended changes according to the objectives and interests identified in Chapter 5, the state of European military capabilities as assessed in Chapter 6, and the analysis of the threat landscape in Chapter 4. The recommendations were then evaluated against alternative postures discussed in Chapter 7 and assessed against several operational scenarios.

Additionally, several assumptions inform the recommendations. Regarding the timeline to enact policy and posture changes, these recommendations are designed for U.S. military force posture in Europe through 2030. In the case of some recommendations that may have a more immediate impact (such as increased port visits) or delayed impact (such as new bases), the approximate timeline will be specified.

Offering recommendations on the future of U.S. posture in Europe is also complicated by the current state of the war in Ukraine. This study assumes that the war will likely continue for the foreseeable future, though the intensity of the fighting could wax and wane based on several factors, including political negotiations. The study assumes that the Russian military will attempt to reconstitute its military forces and capabilities, to include the modernization of the army. China will likely provide economic and some military assistance to Russia to aid in its modernization efforts. The study team also assumes that Iran, North Korea, and other countries will provide military assistance to Russia.

The recommendations offered in this study are not made in a vacuum absent considerations of U.S. posture elsewhere in the world. This report seeks to offer realistic policy options informed by global trade-offs in terms of U.S. forces and capabilities. As outlined above, while the United States has significant interests and objectives, China is the United States’ main geostrategic competitor. Accordingly, this report identifies areas of risk where preferred capabilities may not be available for use in the European theater due to their deployment in the Indo-Pacific theater and offers options to mitigate that risk. The recommendations assume that U.S. tensions with China will continue, including over Taiwan. Finally, this study does not conduct a detailed budget analysis of forward defense, but it does highlight the budgetary implications of certain policies or force posture changes as well as political considerations.

The rest of this chapter examines posture and capability recommendations in the following categories: ground forces, air combat forces, naval forces, air and missile defense, logistics and enablers, ISR, and nuclear forces.

GROUND FORCES

The nature of operations in Ukraine illustrates the continued significance of ground forces in combat in the European theater. Consequently, U.S. ground forces in Europe will play a major role in deterring and responding to acts of Russian aggression and should be strengthened in a “forward defense” posture.

As the war in Ukraine highlights, land warfare remains important, including in Europe. There are several types of capabilities important for achieving U.S. defense objectives highlighted in the previous chapter, including deterring and defeating conventional and nuclear-armed conflict directed against the U.S. homeland and NATO allies. Key examples include:

• Army units, including armored brigade combat teams (ABCTs);

• Main battle tanks, armored personnel carriers, and infantry fighting vehicles;

• Integrated air and missile defense systems;

• Long-range fires;

• Manned and unmanned aircraft;

• Multi-domain command and control; and

• Additional investments and equipment — including logistics — such as munitions stockpiles, spare parts, hardened facilities, and improved lines of communication.

These and other land-based capabilities fall under U.S. Army Europe. In addition, achieving U.S. defense objectives in Europe requires active defenses, passive defenses, and counterstrike. Active defense refers to assets that directly target and eliminate incoming threats, including integrated air and missile defense capabilities, such as Terminal High-Altitude Area Defense (THAAD) and Patriot surface-to-air missile systems (including radars, fire control, battle management, and command and control). Passive defense refers to hardened infrastructure and dispersal of assets through concepts of operation such as agile combat employment (ACE). These passive defense actions minimize damage to installations from kinetic threats by absorbing strikes and forcing U.S. adversaries to expend more munitions on hardened targets. Finally, counterstrike includes the ability to conduct retaliatory actions against enemy forces and to prevent or mitigate damage from additional follow-on attacks.

▲ Figure 6.1: U.S. Military Force Posture in Europe, 2024. Source: Compiled by CSIS based on DOD and open-source reporting.

The United States should prepare for Russia to revitalize its military capabilities and pose a threat to NATO’s eastern flank. It should consequently take steps to strengthen its presence from pre-February 2022 levels by increasing the number of permanent forward-stationed maneuver forces to deter and effectively respond to Russian aggression. That increase entails shifting the rotational ABCT associated with Operation Atlantic Resolve (along with the associated combat aviation brigade) to a permanent, forward-stationed ABCT headquartered in Poland. The United States should also maintain its enduring rotational infantry brigade combat team (IBCT) presence in Romania, as well as rotational deployments to the Baltic states in the near term and incorporate them into Operation Atlantic Resolve under the command of the V Corps headquarters. However, the requirement for these rotational forces may shift depending on changes to the threat environment.

These changes to U.S. ground force posture would shift the U.S. Army to a posture model of four total brigade combat teams (BCTs) in Europe (three permanent, forward-stationed BCTs and one rotational BCT) plus two headquarters in Germany and Poland (four BCTs + two headquarters model) from the previous 3+1 model prior to the war in Ukraine. This model would also include the permanent forward basing of two combat aviation brigades (the existing 12th Combat Aviation Brigade plus another). Prior to the February 2022 invasion, the United States maintained two permanent, forward-stationed BCTs in Europe plus one rotational BCT. The permanent units include the 2nd Cavalry Regiment Stryker brigade combat team (SBCT) headquartered in Vilseck, Germany, and the 173rd Airborne Brigade across Vincenza, Italy, and Grafenwoehr, Germany, as well as the forward-stationed 12th Combat Aviation Brigade. The rotational ABCT, established in the wake of Russia’s 2014 invasion of Ukraine, serves as part of Operation Atlantic Resolve, which deploys approximately 7,000 U.S. Army personnel (including the ABCT plus a combat aviation brigade, sustainment task force, and forward division headquarters) to Europe on nine-month rotations.

Following the 2022 invasion of Ukraine, U.S. ground forces in the U.S European Command (EUCOM) area of responsibility increased significantly, shifting to a 5+2 model with the deployment of two additional BCTs (one ABCT and one IBCT), the V Corps division headquarters in Poland, a High-Mobility Artillery Rocket System (HIMARS) battalion, and enablers. The second IBCT serves as a rotational unit headquartered in Romania to provide an additional brigade on the eastern flank. Additionally, it was announced that the United States would “enhance its rotational deployments” to the Baltics states — including armored, aviation, air defense, and special operations forces — and “maintain a persistent heel-to-toe presence in the region.” From an operational perspective, EUCOM also deployed its permanently forward-stationed forces to NATO’s eastern flank in response to Russia’s invasion, including the 2nd Cavalry Regiment, 173rd Airborne Brigade, Patriot forces, and the 12th Combat Aviation Brigade.

The recommended changes in this report for a 4+2 model would thus maintain the permanent SBCT in Germany and IBCT in Italy and Germany, create a permanent, forward-stationed ABCT at a new base in Poland, maintain the rotational IBCT in Romania, and maintain two permanent headquarters in Germany and Poland.

Forward-stationing an ABCT in Poland offers several benefits to maintaining U.S. interests and achieving objectives in Europe, including (1) providing a credible force to swiftly respond to acts of Russian aggression against NATO partners; (2) reassuring allies of the U.S. commitment while building interoperability with partner forces; and (3) enhancing the general readiness of U.S. forces at large and reducing costs in the long run. Poland would provide the most practical and beneficial location to establish a new military base for an ABCT from an operational and political perspective. As announced at the 2022 NATO summit, Poland already hosts the V Corps Forward Command Post Headquarters, an Army garrison, and sustainment capabilities — the “first permanent stationing of U.S. forces on NATO’s eastern flank.”

More critically, forward-stationing U.S. units in Poland would facilitate the speed of assembly and movement for U.S. operations in Europe, in which ABCTs would play a major role. According to a U.S. Army War College study, “The heart of the combat capability of a division configured for Europe is its ABCTs,” which “provide the bulk of ground force combat power and are the fulcrum around which the remainder of the ground campaign acts.” A forward-stationed ABCT in Poland would limit the amount of time required to build a combat-credible force to counter acts of Russian aggression against NATO. This capability would play a particularly major role in deterring or responding to a contingency in the Baltic states. Russian forces could threaten to cut off or slow the access of U.S. and NATO forces to the Baltic states by closing the Suwalki Gap, also known as the Kaliningrad Corridor — the 40-mile gap between Kaliningrad and Belarus where Lithuania borders Poland. Poland also offers greater strategic depth than alternative locations, such as the Baltic states, and interconnected rail lines with the rest of Europe that would ease resupply and reinforcement efforts.

Forward-stationing a U.S. ABCT where it swiftly reinforces the Baltic states in the event of a contingency would also mitigate risks posed by shortcomings in NATO’s posture and capabilities. As discussed in Chapter 4, European militaries have insufficient numbers of maneuver forces. Moreover, Germany has struggled to expand its forces in Lithuania. However, U.S. and NATO force planners would also have to consider the Russian response to permanently forward-stationing a U.S. ABCT in Poland. The Russian government would likely consider this act to be a provocation and a further violation of the 1997 NATO Russia Founding Act. Consequently, the selection of a specific location for an ABCT base in the country would also have to balance operational efficiency with the risk posed by Russian escalation.

Nevertheless, the permanent U.S. presence would provide greater reassurance to Poland and to allies and partners on NATO’s eastern flank. According to a U.S. Army War College study, ABCTs have an “even greater political salience with Allied policymakers and populations due to their easily understood symbolic value,” and “rotational forces represent less commitment on the part of the United States and so have less reassurance value from the perspective of the ally or partner.” From a political perspective, the Polish government has repeatedly demonstrated its willingness to host a permanent forward U.S. presence and share costs with the U.S. military. Poland already provides significant infrastructure and logistical support for the existing U.S. forces there.

Forward-stationing additional U.S. forces can also enhance interoperability with allied forces and society. Forward-stationed U.S. units develop valuable relationships interacting with host-country military and civilian personnel on a regular basis and become more culturally attuned by learning about the community and environment. There are also vital benefits to increased interoperability both in times of crisis (easier coordination and problem solving) and stability (fewer violations of laws thanks to familiarity with local statutes and practices). As one assessment concludes, “the benefits of tactical and operational interoperability that come with forward stationing are most useful to those units that require the greatest depth of knowledge of local rules, regulations, customs, terrain, airspace, and counterparts.” In the case of Europe, this suggests that ABCTs are best placed to permanently forward station rather than IBCTs or SBCTs.

Interoperability is likely further enhanced when U.S. personnel are forward stationed with their dependents. Military families, about 60 percent of whom live on base, engage with host-country neighbors and businesses as de facto ambassadors. This strengthens strategic interoperability between the United States and host countries by improving cultural understanding and, in the case of Europe, reinforcing transatlantic ties and the role of NATO. When comparing the readiness between forward-stationed and rotational forces, these factors — increased interoperability and the presence of dependents — play a major role in the superior long-term readiness of permanent units compared to rotational forces.

Permanent stationed forces typically have significantly higher unit-manning rates than rotational forces. Manning levels for rotational forces can be as low as 67 percent. Their superior training readiness is further offset by the interoperability and awareness of forward-stationed forces with the host-country military, society, and regulations as well as heightened morale. Some evidence suggests that rotational deployments, which separate military personnel from their families for nine months at a time, cause lower morale than permanent deployments, which keep personnel with their dependents. Rotational deployments also lead to more discipline issues and increased divorce rates. A comparison of re-enlistment rates between rotational BCTs and all Army BCTs found a lower re-enlistment rate for rotational personnel, which was even lower when compared to the forward-stationed 2nd Cavalry Regiment SBCT based in Vilseck, Germany.

From a force-planning and budgetary perspective, the costs of permanently stationed forces are also lower. In terms of the force-generation model, an enduring and constant rotational ABCT presence in Europe for a nine-month deployment requires three total ABCTs. As an illustrative example, U.S.-based ABCT-1 must be training and preparing to deploy to replace ABCT-2 currently in Europe. ABCT-3, also U.S.-based, after recently ending its nine-month deployment, must then recover and begin training to deploy following ABCT-1’s tour overseas. This model, rather than having one unit permanently stationed in Europe, eats up more of the Army’s force structure and long-term readiness.

From a fiscal cost perspective, establishing a new U.S. military base in Poland would initially have high budgetary costs and take roughly seven years to put in place. However, the financial burden of permanently stationed forces would be lower in the long run. Operation and sustainment costs would be significantly lower than those of rotational force. A forward-stationed ABCT incurs 75 percent of the additional operational tempo (OPTEMPO) costs that a rotationally deployed ABCT would, and it also generates savings over time. Moreover, given the cost of moving their equipment, ABCTs are the most expensive unit to rotationally deploy, suggesting that IBCTs or SBCTs are better suited to that deployment model.

Long-Range Fires: Long-range fires offer a valuable capability to deter Russian aggression on NATO’s eastern flank, as evidenced by the reactivation of the 56th Artillery Command in Germany and the activation of the Army’s 2nd Multi-Domain Task Force in 2021. Long-range fires units, including those with HIMARS capabilities, have also deployed on a rotational basis to conduct training and improve interoperability with NATO allies. In March 2023, the Army’s V Corps announced its European HIMARS initiative to formalize these efforts, particularly across the eastern flank, with participation from 56th Artillery Command, 41st Field Artillery Brigade, and elements of the 101st Airborne and 4th Infantry Divisions.

Given the applicability of the capability to operations in Europe as well as the Indo-Pacific, long-range fire units must be balanced across both theaters. European militaries, however, lack a strong long-range indirect fire capability, as discussed earlier. The United States can increase its capabilities in Europe by permitting further sales of HIMARS systems to NATO allies. Between 2022 and 2023, the United States completed sales of HIMARS systems to Estonia, Poland, and the Netherlands. To enhance allied lethality, the Army should also continue rotational deployments of HIMARS units in support of the European HIMARS Initiative. Furthermore, the Army should continue the modernization of the long-range fires, to include the development of hypersonic capabilities and fielding of the Precision Strike Missile (PrSM) to replace existing HIMARS and multiple launch rocket systems (MLRS) munitions.

Special Operations Forces and Security Force Assistance Brigades (SFABs): U.S. special operations forces and U.S. Army SFABs are helpful in such areas as:

• Foreign internal defense, which involves efforts to build the capacity of foreign governments. This can include training and equipping partners in Europe that border Russia, such as Finland, Latvia, Lithuania, Estonia, and Poland. Special operations forces are an essential part of foreign internal defense. These activities can also include broader efforts to conduct security force assistance.

• Unconventional warfare, which includes operations to advise, assist, and accompany non-state partners resisting a hostile actor by operating with or through an underground, auxiliary, and guerrilla force.

• Information operations — or Military Information Support Operations — which involve activities to influence foreign audiences.

There are other critical activities, such as special reconnaissance, civil affairs operations, direct action, counterterrorism, counter-proliferation of weapons of mass destruction, counterinsurgency, and hostage rescue and recovery. Special operations forces can counter Moscow economically, militarily, and diplomatically below the threshold of conventional war — including through information operations. For example, U.S. forces can also proactively highlight examples of Russian malign activity, human rights abuses, and corruption. Examples of subjects that could be highlighted include:

• Russian direct or indirect involvement in human rights abuses, including in Ukraine;

• Russian involvement in the assassination (or attempted assassination) of defectors, political opponents, and those — such as journalists and lawyers — investigating or prosecuting Russian corruption or human rights abuses;

• Russian proxies involved in abuses, including Russian private military companies such as the Wagner Group;

• Corruption in Russia, including by senior Russian officials;

• Russian support to terrorist and insurgent groups, such as the Taliban in Afghanistan and Lebanese Hezbollah and Shia militias in Syria;

• Russian economic problems; and

• Anti-regime riots, protests, and demonstrations in Russia or in Russian-allied countries, such as Belarus.

The U.S. military should increase efforts to build and enhance allied and partner capabilities, with a focus on eastern flank states. The United States has already undertaken significant and credible missions to train partner forces in the Baltics and Ukraine since Russia’s 2014 invasion of Ukraine by deploying special operations forces, the Army’s 4th SFAB, and Army National Guard units. U.S. special operations forces units have taken the lead in training Baltic militaries to counter Russian hybrid and irregular warfare capabilities. To that end, as well as to establish a forward operating site, U.S. forces established a new special operations site in Riga, Latvia, in 2020. The U.S. security cooperation efforts in the region are simultaneously boosted by the National Guard’s State Partnership Program, which assigns certain National Guard units from specific states with partner countries to train forces there. The 4th SFAB similarly operates between the “Baltics and the Black Sea” and, as of September 2022, had 19 teams of military advisers in 10 European countries.

Forces from the 4th SFAB have also been involved in the training of Ukrainian personnel. However, that effort has been led by the Joint Multinational Training Group-Ukraine (JMTG-U) under the direction of the Security Assistance Group-Ukraine (SAG-U). National Guard units, including a New York State BCT, have trained Ukrainian forces under the JMTG-U to great effect. Where possible, the United States should increase its training of Ukrainian units and personnel to strengthen their ability to withstand and counter further Russian aggression. This should be complemented by an expansion of training programs with the militaries of the Baltic states and other relevant Eastern flank states to defend against hybrid Russian threats. Special operations forces may also provide civil defense training practices to those populations in the event of a heightened or resurgent Russian threat.

However, the United States should also take steps to ensure greater coordination among its various security cooperation efforts in Eastern Europe. The Department of Defense (DOD) should assign one entity to lead and manage security cooperation missions in the region to ensure the efficient allocation of units and resources.

AIR COMBAT FORCES

Air capabilities are critical to achieve U.S. defense objectives, including deterring and defeating armed conflict, countering terrorist and other transnational threats, and maintaining access to trade routes and global commons. Russia has considerable air and air defense capabilities, such as the S-400, which would undermine the United States’ ability to gain air supremacy in a war.

For future U.S. posture, there are several important categories of air assets. First, fixed-wing aircraft, such as F-35, F-16, and F-15 squadrons, are helpful for conducting close air support, suppression of enemy air defense, combat air patrol, defensive counter air, strike, and other missions. So are bombers, such as the B-52H Stratofortress and B-21 Raider, which can be useful to attack ground and naval targets. Second, ISR capabilities are important for intelligence and warning. Examples include unmanned aircraft systems (such as the RQ-4 Global Hawk, MQ-9A, and MQ-9B); airborne early warning and command and control (such as the E-8 Joint STARS, E-3 Sentry, and E-7); and electronic warfare. Along with space capabilities, persistent aerial ISR is critical to collect intelligence, including communications and electronic intelligence. Third are enablers, including transport (such as the C-17 and C-130), aerial refueling (such as the KC-135 and KC-46), and medical evacuation. Fourth are logistics, such as stockpiling spare parts and munitions, personnel, and petroleum, oil, and lubricants.

Global posture considerations play a major role in recommendations for the air domain in Europe given the value of air combat capabilities in the Indo-Pacific theater. Consequently, a forward defense posture that enhances deterrence should ensure flexibility in the air domain to surge forces to the Indo-Pacific if necessary. It also means that the United States needs to be prepared to accept some risk that can be mitigated through allied capabilities.

In terms of air combat capabilities, a forward defense posture includes maintaining all seven forward-deployed fighter squadrons currently based in Europe and adding an additional F-16 squadron to Spangdahlem Air Base. Four squadrons are based at Royal Air Force (RAF) Lakenheath in the United Kingdom under the 48th Fighter Air Wing, including two squadrons of F-35A aircraft and 2 F-15E squadrons. Two squadrons of F-16 aircraft are stationed at Aviano Air Base in Italy under the 31st Fighter Wing, and one additional F-16 squadron is currently stationed at Spangdahlem Air Base in Germany under the 52nd Fighter Wing. While stationed out of their respective bases, these units have often been forward deployed to NATO’s eastern flank to provide additional posture amid the war in Ukraine.

Forward-stationed forces are supplemented by deployments of U.S.-based fighter aircraft to enhance the United States’ forward posture, increasing in the lead-up to and throughout the Ukraine conflict. These supplemental units have included active-duty, reserve, and Air National Guard F-35 units operating out of Spangdahlem Air Base and forward-deployed to allied air bases on the eastern flank in support of NATO Enhanced Air Policing Missions, as well as U.S.-based F-22 and fourth-generation aircraft.

Forward-deployed F-35 squadrons enhance the capabilities of U.S. and allied forces to establish air superiority against robust and experienced Russian integrated air defense systems (IADS). F-35 aircraft can also collect electronic signals from and compile a picture of hostile and friendly forces in an area. However, given requirements for the Indo-Pacific region, adding another F-35 squadron to the two currently stationed at RAF Lakenheath is not optimal.

Instead, this analysis recommends forward stationing an additional F-16 squadron at Spangdahlem Air Base to provide greater short-term combat capacity as allied F-35 squadrons come online. Additional permanently based fifth-generation squadrons in Europe may be more likely to come as future replacements for the Air Force’s F-15E squadrons, which the service plans to cut by more than half by 2028. F-16 fighters, such as those currently based at Spangdahlem and Aviano Air Bases, will likely continue to serve into the 2040s. However, U.S. Air Forces in Europe should supplement these aircraft with deployments of U.S.-based fifth-generation squadrons of fighter aircraft — either F-35 or F-22 aircraft — as demanded by the threat environment.

As previously discussed, ACE will continue to play a vital role in maximizing the flexibility and survivability of forward-deployed fighter aircraft. ACE will require U.S. aircraft and pilots to operate and rapidly deploy from forward operating sites on allied and partner airfields as part of a hub-and-spoke system. These sites should be “light, lean, and agile,” as noted by General CQ Brown. However, the Air Force needs to ensure that its dispersed sites are equipped with adequate prepositioned equipment and war reserve materiel, including scalable logistics packages, resilient communications, command and control, munitions, spare parts, and petroleum, oil, and lubricants; are resilient from missile and cyber attacks; have adequate infrastructure for storing munitions, fuel, and other materiel; and have forces trained for quick response to enemy missile attacks, including runway repair and medical care.

To further maximize flexibility, U.S. air combat forces based in or deployed to Europe must also be prepared to surge to the Indo-Pacific in the event of a contingency. The Air Force has already leveraged EUCOM assets to fill capability gaps in the Indo-Pacific with the temporary transfer of F-16 aircraft from the 52nd Fighter Wing at Spangdahlem Air Base to Kadena Air Base in Japan amid the return of its F-15C/D fighter aircraft to the United States. The Air Force and NATO must prepare plans to fill its own capability gaps in the event of further transfers.

NAVAL FORCES

To achieve defense objectives in Europe, the United States will likely need several types of maritime capabilities led by U.S. Naval Forces Europe-U.S. Sixth Fleet. Maritime capabilities will be helpful to deter and defeat conventional armed conflict, counter irregular and gray zone activities, maintain access to trade routes and global commons (including in the Arctic), and other objectives. The Russian navy possesses significant maritime capabilities, such as submarines, and it has added the Project 955A Borey-A nuclear-powered ballistic missile submarine (SSBN) and the Project 08851 Yasen-M nuclear-powered guided missile submarine to its fleet. European maritime capabilities, as previously discussed, are likely lacking in large-scale combat, given qualitative shortfalls in sensors, weapons, force protection, and survivability systems as well as due to manning, maintenance, and procurement challenges for some navies.

To fully leverage its naval capabilities in Europe and compensate for the shortcomings of allied and partner militaries, the United States should expand operations, port visits, and exercises in partnership with allied and partner forces and consider investments in future capabilities to deploy to Europe. However, the United States also needs to pursue flexibility and mitigate risk in its posture given requirements in the Indo-Pacific theater.

The U.S. Sixth Fleet, headquartered at Naval Support Activity (NSA) Naples, Italy, conducts and oversees naval operations in the European theater. The Sixth Fleet maintains six destroyers homeported in Rota, Spain, as part of Task Force 65. These destroyers play a critical role in NATO’s ballistic missile defense mission under Operation Atlantic Sentry. The vessels also conduct regular Forward-Deployed Naval Forces-Europe (FDNF-E) patrols throughout the Sixth Fleet area of operations to conduct port visits and strengthen interoperability with allied and partner forces. In addition to the destroyer presence at Rota, the United States also conducts regular carrier strike group deployments and occasional amphibious ready group/Marine expeditionary unit deployments, the latter of which falls under the Sixth Fleet’s Task Force 61/2.

To achieve a posture of forward defense in the European area of operations, the United States should enhance its naval presence in the Baltic Sea region with small surface combatants and unmanned vessels through 2030 to reassure and improve interoperability with allies and partners in the region and to deter potential acts of Russian aggression. Russia still maintains a sizeable presence in the region. In 2022, the Swedish government requested a strengthened U.S. naval posture in the region. U.S. ships should conduct more frequent port visits, including both FDNF-E patrols and deployments of U.S.-based assets, as well as bilateral and multilateral exercises.

The United States must also act in coordination with its NATO allies to tackle several mission sets. Anti-submarine warfare (ASW) remains a critical mission, both in the Baltic and North Seas, which has been much neglected. NATO has consequently increased its joint ASW exercises among allied forces, including Operation Dynamic Mongoose in the North Atlantic in 2022 and Dynamic Manta off the coast of Italy in 2023.

The U.S. Navy could supplement existing NATO ASW capabilities by developing and deploying additional systems to the region. One option is homeporting the U.S. Navy’s Littoral Combat Ship, which has ASW capabilities, in German ports to provide improved situational awareness in the Baltics. Given the Navy’s apparent commitment to retire the Littoral Combat Ship, it could deploy its Constellation-class frigates, which also have ASW capabilities, to the region once they are operational beginning in 2027. However, operational requirements for the presence of surface ships and submarines in the Indo-Pacific should take priority over Baltic deployments.

Given Indo-Pacific demands for naval forces, the Navy could also leverage its developing unmanned surface and undersea vessels for ASW and additional missions in the Baltic Sea. Pioneered under the Fifth Fleet’s Task Force 59 in U.S. Central Command (CENTCOM), the Navy recently announced its intention to deploy these capabilities to the broader fleet beginning with Fourth Fleet under U.S. Southern Command (SOUTHCOM) in the summer of 2023. The United States and partners should also increase their number of sonobuoys and static hydrophone networks to track the subsurface threat.

The U.S. Navy and NATO allies should additionally prioritize three maritime missions in the Baltic region: hybrid gray zone operations, offensive and defensive mining, and missile defense and suppression. They must develop a plan to tackle hybrid threats to undersea cables and pipelines and other infrastructure that could disrupt the flow of commerce, energy, and data. This is critical to managing escalation and preventing Russia from destabilizing the region. Furthermore, the United States and NATO should plan to leverage the extensive mining and demining capabilities of new members Finland and Sweden in the event of a possible contingency with Russia that threatens naval deployments and the commercial shipping of partners and allies. Finally, the United States and NATO must anticipate the use of anti-ship cruise missiles in a potential conflict with Russia and seek to neutralize this threat through the coordination of the Baltic Air Policing mission and Allied Maritime Command.

As the Navy expands its mission set and presence in the Baltic and North Seas, it should strengthen its forward posture by considering homeporting vessels in the region or establishing logistical points to resupply, given the distance from existing sites in Spain, Italy, and Crete. While this would require significant diplomatic outreach, the Navy could explore the possibility of establishing sites at existing ports or naval bases in Germany, Denmark, or other allied states.

In the Black Sea, the United States must work with its NATO allies and partners in the region to enhance its maritime domain awareness. The United States and the NATO alliance should encourage regional partners to cooperate and modernize their military capabilities, including by strengthening sea power in ways that are consistent with the Montreux Convention. The United States should also increase engagement with allied and partner militaries in the region. This could include seeking a more active partnership with the Turkish military in the Black Sea as part of a broader agreement to improve U.S.-Turkish strategic cooperation on a handful of key issues.

The Arctic represents another vital region for U.S. maritime interests. The United States should expand its capabilities and posture in the Arctic through the U.S. Coast Guard. The 2022 National Strategy for the Arctic Region outlined security as one of its four strategic pillars for the region. The strategy called for “expanding the U.S. Coast Guard icebreaker fleet to support persistent presence in the U.S. Arctic and additional presence as needed in the European Arctic.” The primary goal of U.S. forces in the region is to support the homeland defense mission as well as power-projection and deterrence goals, alongside safeguarding commercial and scientific activities. While the strategy primarily emphasizes the need to deter aggression from Russia in the Arctic, it also notes expanded Chinese activities there. Russia seeks to maintain its economic interests, such as oil and gas megaprojects, in the region while leveraging the Arctic for greater power projection and potentially hybrid activities to threaten European Arctic countries. Russia currently operates more than 40 icebreakers. China has increased its presence and posture in the Arctic, maintaining three research sites in Svalbard, Iceland, and Sweden and operating two icebreakers, with a third under development.

The United States should seek to expand its Arctic posture and capabilities as rapidly as possible to counter Russian and Chinese security interests in the region. Currently, the U.S. Coast Guard only operates two icebreakers, the heavy cutter Polar Star and the medium cutter Healy, neither of which can be used for all-year Arctic icebreaking missions. The Coast Guard plans to expand its icebreaking fleet with the procurement of three heavy Polar Security Cutters (PSCs), although delays have pushed the delivery of the first vessel back to 2026 or 2027, and three medium Arctic Security Cutters (ASCs). In 2021, then-commandant of the U.S. Coast Guard Karl Schultz called for a fleet of nine total icebreakers (six PSCs and three ASCs). As the United States awaits delivery of its new vessels, it should seek to enhance cooperation with Arctic allies through joint operations and combined exercises and training.

LOGISTICS AND ENABLERS

This section examines several types of logistics and enablers, including prepositioned equipment and munitions stockpiles, ISR, integrated air and missile defense, and infrastructure and mobility.

Prepositioned Equipment and Munitions Stockpiles: The United States should take steps to bolster its prepositioned equipment and munitions stocks in Europe to enhance the readiness of U.S. forces in the event of a contingency with Russia. The Army maintains its Army Prepositioned Stock-2 (APS-2) across four sites in three different countries (Germany, Belgium, and the Netherlands), with a fifth APS-2 site planned for Poland. These sites, operated by the 405th Army Field Support Brigade, contain enough materiel to equip two ABCTs. The Army issued some of this stock in March 2022 to the 1st ABCT, 3rd Infantry Division in the wake of Russia’s invasion of Ukraine. While APS-2 stocks have been bolstered by funding from the European Deterrence Initiative, the Army should take additional steps to improve the readiness of this equipment and the forces overseeing it. A DOD inspector general investigation found that some materiel provided from APS-2 was “non-fully mission capable” and that “maintenance and coordination shortfalls occurred.” In the event of a direct conflict against Russia, U.S. forces arriving in theater must be assured that they will receive capable equipment to rapidly equip and engage the enemy.

In addition to enhancing prepositioned equipment, the DOD must ensure that EUCOM is maintaining appropriate inventories of munitions in the region. The war in Ukraine has illustrated the role of long-range artillery, and U.S. and NATO forces must have enough missiles and munitions in theater to contend with and counter Russian forces. That includes munitions for the Air Force, which must develop plans to maintain weapons for aircraft operating under the ACE concept at forward locations, and the Army EUCOM’s munitions starter stocks, which preposition key munitions — including Patriot Missile Segment Enhancement — in Europe for use in the event of a contingency. Additionally, EUCOM should seek to reinforce and build additional facilities to store munitions to distribute across the theater for easier access and enhanced survivability.

Intelligence, Surveillance, and Reconnaissance: The demand for U.S. ISR assets will only increase as the U.S. military expands missions and operations in the Indo-Pacific and the Russian military reconstitutes its capabilities on NATO’s eastern flank. While the United States should prioritize the Indo-Pacific, the DOD should maximize its available ISR assets for use by both EUCOM and U.S. Indo-Pacific Command (INDOPACOM). The DOD is currently seeking to modernize its ISR capabilities, with plans to retire the RQ-4 by FY 2027 and the MQ-9 by FY 2035. However, the DOD and the services must ensure that any gaps in ISR coverage are limited. This could be managed by timing the retirement of certain platforms to coincide with the activation of new assets. Alternatively, the DOD could leverage commercial capabilities to cover any gaps until requirements are established and new platforms are deployed.

The Army is currently testing commercial assets in operations in Europe under its High Accuracy Detection and Exploitation System (HADES) to define the requirements for the replacement for the RC-12 Guardrail aircraft.

Space-based ISR assets will play a major role in both covering gaps and supplementing ISR provided by traditional airborne assets. Commercial satellite imagery has already been used by NATO to fill gaps in coverage and played a major role in identifying Russian military movements in the lead-up to the 2022 invasion of Ukraine. In the next few years, the United States should further leverage commercial satellite imagery to bolster its ISR capabilities in Europe. Over the long term, however, the DOD must ultimately determine the appropriate balance between leasing commercial services and establishing its own systems to ensure sustainable and reliable coverage.

Integrated Air and Missile Defense: Some changes to U.S. air and missile defense posture should be made in the event that some of the recommendations here are adopted, including the permanent basing of an ABCT in Poland. If a new base is established, the United States should consider shifting the headquarters of the 10th Army Air and Missile Defense Command from Rhine Ordnance Barracks in Germany. A new base in Poland would require a significant investment in air and missile defense capabilities given its proximity to Russia. If the Army chooses not to move the entire command to Poland, it should prioritize shifting the battalion headquarters of the 5th Battalion, 7th Air Defense Artillery Regiment, which provides command and control operations of Patriot batteries, and the 5th Battalion, 4th Air Defense Artillery Regiment and its short-range air defense capabilities.

From a broader force-planning perspective, however, the Army should prioritize the deployment of additional Patriot battalions, which operate at the highest OPTEMPO of Army units and are in high demand from multiple combatant commands. Given their value in potential conflicts with China and Russia, the Army should create additional units to limit the stress and degradation of readiness of existing units, particularly given the lack of European capabilities in this area.

In terms of ballistic missile defense, the United States should also maintain its current posture and force structure in line with Operation Atlantic Sentry. Relevant units include the six Aegis destroyers homeported in Rota, Spain, along with the two Aegis Ashore sites based in Romania and Poland.

Infrastructure, Mobility, and Access: The United States, in partnership with host nations and other NATO allies, should also take steps to improve military infrastructure and mobility to ensure ease of access, transportation, and reliable communications throughout the European theater. These include enhancements to infrastructure on both U.S. bases and in partner countries, such as the installation of fiber-optic cables and improvements to rail, road networks, and bridges. The DOD and European Defence Agency have identified military mobility as one area of collaboration under an Administrative Arrangement reached in April 2023 (see security cooperation section below).

The United States should also continue to update its security and defense cooperation agreements with its partners and allies to ensure ease of access. In December 2023, the United States reached new agreements with Sweden, Finland, Denmark, Estonia, Latvia, and Lithuania that provided U.S. forces with access to bases and other infrastructure in those countries.

NUCLEAR POSTURE

The United States should continue with planned nuclear modernization efforts, exercises, and scheduled deployments of assets to the European theater to bolster its deterrent capabilities and reassure allies. The United States currently deploys 100 tactical bombs — the B61-3 and B61-4 gravity bombs — in air bases in Europe across five countries. Under current U.S. nuclear-sharing policy, control over those bombs is maintained by the U.S. Air Force, but seven countries contribute dual-capable aircraft to the mission (Belgium, the Netherlands, Germany, Italy, Turkey, Greece, and the United States) and four air forces (from Belgium, the Netherlands, Germany, and Italy) are assigned an active nuclear strike role with those weapons in the event that a nuclear mission is approved.

The United States is currently in the process of modernizing its gravity bombs, with the new B61-12 having begun full-scale production in 2022 and deployment originally planned for the spring of 2023.

A range of U.S. and allied dual-capable aircraft will be certified to operate the B61-12, including the F-15E, F-35A, F-16, B-2, and German PA-200 Tornado (currently planned to be retired and replaced by the F-35A by 2030).

NATO is also modernizing its nuclear weapons storage facilities, including making upgrades to command and control structures and base security.

The U.S. military and NATO should also continue to conduct exercises with nuclear-capable platforms, including Bomber Task Force missions, to enhance readiness and assure allies of U.S. support. These include the annual NATO Steadfast Noon exercise, which practices nuclear sharing. However, such exercises should occur on a regularly scheduled timeline to ensure consistency and limit the potential for escalation with or misinterpretation by Russia. There is no evidence that unscheduled Bomber Task Force deployments conducted under the dynamic force employment model offered additional deterrent value, particularly given the still lengthy amount of time necessary to organize such missions.

CYBER AND SPACE

In the cyber and space domains, U.S. forces should take steps to enhance the security and resilience of their own systems and networks while simultaneously assisting European partners and allies in securing their own capabilities. U.S. Cyber Command (CYBERCOM) should deploy additional “hunt forward” teams to Europe in line with its “defend forward” strategy to counter threats from Russia and Russian-backed groups to U.S. forces and allies. CYBERCOM deployed its largest hunt forward team to Ukraine between 2021 and 2022. To capably resource further deployments and ensure readiness, CYBERCOM should also seek to expand the number of cyber mission teams across the services.

The United States should further define its authorities for and consider expanding its conduct of offensive cyber operations against Russian forces, particularly in the event that the conflict in Ukraine and Russian cyberattacks persist. The United States should also expand deployments of U.S. Space Force units and personnel to Europe and define their role within NATO. The service is currently standing up its own component to operate in EUCOM. Space Force units can play a major role in supporting forward-deployed U.S. forces by preventing enemy interference and maintaining open lines of satellite communication. Additionally, space-based ISR assets will continue to play a major role in the European theater, and the U.S. military should also further leverage commercial capabilities to fill gaps.

Finally, U.S. forces should enhance redundancy, in addition to improving the resilience of U.S. assets and networks in terms of both software and hardware. Establishing clear fallback options for communications and ISR in the event of a contingency is vital to ensuring the survivability of networks.

SECURITY COOPERATION

In addition to maintaining and bolstering traditional partner capacity-building efforts, the DOD, in tandem with EUCOM and the U.S. Department of State, should adopt a broader approach to security cooperation in the region. This would entail supporting the efforts of NATO allies and other European partners to develop and acquire advanced military capabilities and lessen their reliance on U.S. units and platforms, particularly enabling forces that support operations.

▲ Figure 6.2: U.S. Nuclear Posture in Europe. Source: Compiled based on data from Hans Kristensen and Matt Korda, Federation of American Scientists, 2023, and Nuclear Disarmament Resource Collection, Nuclear Threat Initiative.

As part of this effort, the DOD should consider standing up a new organization within EUCOM to coordinate broader U.S. security cooperation efforts in Europe. This organization should have representation from the services, the Office of the Under Secretary of Defense for Policy, and the Defense Security Cooperation Agency, and work closely with the Department of State. It would directly interface with NATO headquarters and allied militaries to manage requests for security assistance and arms sales, as well as provide guidance on the development of new capabilities, as needed. The organization’s objective would be to bolster allied and partner capacity by focusing on closing quantitative and qualitative gaps within European militaries that drive their reliance on U.S. forces in some areas. It could also pursue greater coordination and information sharing between the United States and European allies in the development of new technologies and capabilities, thereby ensuring interoperability.

The DOD has already taken some steps to bolster cooperation efforts and information sharing with European partners in its April 2023 Administrative Arrangement reached with the European Defence Agency (EDA). The agreement provides a framework for the United States and EDA to “exchange information and explore collaborative activities falling within the scope of EDA’s mission,” with a focus on areas including supply chain issues, military mobility, and the impact of climate change on defense activities. However, the terms of the agreement specifically preclude “research and technology” from the scope of the arrangement.

CONCLUSION

The recommendations outlined in this chapter seek to enhance U.S. military posture from its levels before the 2022 Russian invasion of Ukraine. While this posture strengthens the ability of the United States and NATO to deter and repel Russian aggression on the continent, it also pursues more sustainable policies by shifting the presence of U.S. ground forces largely to permanent, forward-stationed forces and articulates trade-offs and limitations with other strategic pri orities, such as competition with China in the Indo-Pacific region. Moreover, it seeks to accommodate both the benefits and shortcomings of allied capabilities in the region.

CH. 07

ALTERNATIVE OPTIONS

The recommendations for the future of U.S. military posture in Europe, as outlined in the preceding chapter, provide the necessary forces and capabilities to realize the United States’ interests and strategic objectives outlined in Chapter 5. There are, however, alternative military postures to this “forward defense” approach that the United States could adopt based on different interests and objectives. This chapter briefly assesses the components of alternative U.S. posture options for Europe through 2030, along with their associated advantages and limitations.

This chapter focuses chiefly on three broad approaches: an extension of the U.S. military’s current posture in Europe in response to Russia’s invasion of Ukraine; a strategy of restraint; and a China-first strategy that strictly prioritizes competition with China above all other objectives. It should be noted that the latter two strategies do not represent a singular, cohesive approach that is uniformly agreed upon by their advocates. Similarly, there is overlap in the views and advocates of these two approaches. While these strategies may offer some benefits to U.S. foreign policy, such as prioritizing resources for competition in the Indo-Pacific, their significant cuts to U.S. posture in Europe would severely undermine the ability of the United States and NATO to deter and respond to threats from a revanchist Russia.

MAINTAIN CURRENT U.S. POSTURE

One alternative is to extend the U.S. military’s existing posture in Europe, as currently oriented in response to Russia’s invasion, through 2030. This posture is based on an operational concept of deterrence by denial, and it relies on an enhanced military presence, as illustrated by the United States’ current end strength of approximately 100,000 personnel in Europe. The U.S. military would maintain that posture throughout the time frame or until European allies bolster their capabilities and capacity to reinforce NATO’s eastern flank.

Such a posture would be based on the current 5+2 model that maintains five total brigade combat teams (BCTs), including the two additional BCTs deployed after Russia’s invasion (one rotational armored brigade combat team [ABCT] and one rotational infantry brigade combat team [IBCT] in Romania) in addition to the pre-war units (a forward-stationed IBCT and Stryker brigade combat team [SBCT] based in Italy and Germany, respectively, and one rotational ABCT as part of Operation Atlantic Resolve). The model would keep headquarters in Germany and Poland as well. In terms of air combat forces, this posture would maintain the seven fighter squadrons currently forward deployed and add a persistent rotational deployment of fifth-generation aircraft to NATO’s eastern flank. Other force structure elements would remain largely unchanged from the status quo.

The current U.S. military posture provides greater combat capability for U.S. and allied forces in Europe with the deployment of an additional ABCT, which could consequently provide increased deterrent value against Russia. This strengthened posture also serves to reassure European allies, particularly those on the eastern flank, of the United States’ commitment. However, there are drawbacks to maintaining this enhanced posture over the long term. While a second ABCT provides greater combat capability and potential deterrent value, it does not ensure that NATO would be able to defeat a determined Russian invasion on the eastern flank, particularly an attack against the Baltic states, where there is limited strategic depth.

Maintaining the current enhanced military posture in Europe would also force the United States to incur greater costs in terms of operating expenses and readiness. As discussed in the preceding chapter, rotationally deployed units are more expensive from both a cost and readiness standpoint than forward-deployed units. Two rotational ABCTs would put greater stress on the Army’s force-generation model, given the time and additional units required to replace following the end of their deployment. While constructing a permanent military base in Poland would entail costs in the short-term, it would prove more sustainable over the long term and allow units to integrate into the local community.

Finally, maintaining the current 5+2 posture model in Europe risks encouraging free riding from U.S. allies and delaying their efforts to strengthen their own military capabilities in terms of both force size and modernization. The recommended 4+2 model, with a permanent forward-stationed ABCT in Poland, highlights U.S. long-term resolve and commitment while also stressing that NATO militaries must swiftly enhance their forces and posture on the eastern flank in the short term.

STRATEGIC RESTRAINT

Strategic restraint, sometimes called offshore balancing, argues that the United States is fundamentally secure based on its relative geographic isolation, nuclear arsenal, and military power. According to this view, the United States has over-extended itself with costly overseas commitments and misguided interventions in countries and missions that are not critical to U.S. interests. Consequently, advocates for strategic restraint call for the United States to draw down its global military presence and missions to focus on more limited objectives, to include homeland defense or preventing rivals from disrupting the global or regional balances of power.

Advocates for strategic restraint largely argue for a drawdown or the complete withdrawal of U.S. forces from Europe. Some have even called for reconsidering the United States’ membership in NATO, although that is by no means a universally shared view within the restraint community. While restraint is a broad and ideologically diverse approach, most advocates agree that the United States should end or significantly reduce its military presence in Europe on geopolitical and budgetary grounds.

While advocates call for a reduction of U.S. forces in Europe, they have yet to offer detailed analysis of the future U.S. posture they envision and the force elements that would remain on the continent. However, the main component of a restraint force posture would entail a reduction in U.S. presence from Europe over 5 to 10 years to the eventual withdrawal of most U.S. forces. The United States would end access agreements with European partners and either close or repurpose most of its bases, predominantly Army bases. For example, Massachusetts Institute of Technology professor Barry Posen calls for remaining bases to be converted to forward operating sites or cooperative security locations for use in the event of a contingency. Forces along the eastern flank, including the rotational ABCT presence in Poland and the IBCT in Romania, would be removed.

Nonetheless, some U.S. forces would likely remain in theater. In terms of ground forces, the United States could retain its forward-stationed IBCT to serve as a contingency response force, and special operations forces could also retain a small footprint to realize limited U.S. objectives on the ground. While the United States would withdraw its F-35 squadrons from the United Kingdom, it could retain its F-15E presence at Royal Air Force (RAF) Lakenheath and consider maintaining its F-16 presence at either Spangdahlem or Aviano Air Bases.

In terms of the maritime domain, the United States could retain naval bases, including in Rota and Naples, and forces to ensure freedom of navigation at sea and U.S. command over the maritime commons. Finally, the United States may seek to maintain some nuclear weapons in Europe and the nuclear-sharing mission to counter major aggression from Russia. To compensate for the lack of forces in the area, it may opt to increase stocks of prepositioned equipment for use in the event of a contingency.

Supporters argue that the primary benefit of adopting a posture of restraint in Europe would be to free up forces and resources that could be allocated elsewhere, since many believe that the United States is “not capable of conducting full-scale operations against China and Russia simultaneously.” The strategy of restraint would reduce the U.S. position in Europe to a supporting role, which advocates justify by arguing that its NATO allies and the European Union possess enough military and economic power to counter Russian forces and other security crises. The United States could then prioritize allocation of resources toward other priorities, such as strategic competition in the Indo-Pacific.

Moreover, advocates of restraint argue that withdrawing forces from Europe would significantly reduce the challenge of free riding by NATO allies and encourage greater European investment toward defense capabilities. While other NATO allies have lagged behind the United States in terms of security investment, supporters of strategic restraint argue that the strong U.S. presence in Europe has “long suppressed” the development of indigenous defense capabilities on the continent and hindered cooperation between European states. Withdrawing U.S. forces would require Europe to invest much more significantly in its own defense and would result in budgetary savings for the United States.

Despite these arguments, the drawbacks of a restraint-based posture in Europe outweigh its advantages. First, a significantly reduced U.S. presence would incur significant risk and potentially embolden a revanchist Russia to pursue acts of aggression against states on the eastern flank. As argued in Chapter 3, Russia is actively modernizing and rebuilding its military with some help from China, Iran, and other countries. In the event of a contingency, U.S. forces would take longer to deploy from the United States and respond to threats against NATO.

Second, while allies and partners may invest more in their own defense, they would likely not be able to develop the forces and capabilities necessary to compensate for withdrawn U.S. forces even in the event of a phased drawdown over several years. As outlined in Chapter 4, while European nations are largely able to perform small-scale military missions and some medium-scale missions without U.S. assistance, they typically require U.S. collaboration to successfully execute large-scale operations. European forces rely heavily on the U.S. military for assistance in areas such as intelligence, surveillance, and reconnaissance (ISR), logistics support, long-range precision support, heavy maneuver forces, and maritime operations. Most lack capacity in their defense industrial base to indigenously develop the required systems in a short time frame, and many face ongoing personnel and equipment shortages, interoperability challenges, and uncertain future funding for efforts such as air and naval patrol missions.

Finally, advocates of restraint overstate the budgetary savings associated with reducing the overseas presence of U.S. forces. To generate significant savings, the Department of Defense would have to wholly eliminate units and divest equipment rather than simply return U.S. units and personnel to the contiguous United States. In addition to being politically and logistically difficult, such eliminations would leave the U.S. military unable to redeploy forces to other theaters such as the Indo-Pacific — thus negating the first and most important benefit that restraint advocates hope to achieve.

Together, the detrimental effects of a force posture based on restraint would outweigh its alleged benefits. Such a posture would create significant security risks and operational gaps across the European continent without producing meaningful savings for the United States.

CHINA FIRST

A China-first strategy shares similar underpinnings to the “offshore balancing” strain of restraint. Advocates of this approach argue that U.S. forces and resources dedicated to European security and, more specifically, to Ukraine in its conflict with Russia undermine the United States’ ability to compete with China in the Indo-Pacific and to defend Taiwan. Advocates of a China-first strategy argue that if Taiwan is taken by China, the United States’ military position in the region and the confidence of Asian partners states in the ability of the United States to confront China would weaken. Members of the restraint community note that the alignment of China-first “hawks” with foreign policy realists has “reshaped” the debate over U.S. security commitments to Europe. However, restraint advocates generally do not view the China threat as urgent as China-first supporters do, while some view U.S. interests in the Indo-Pacific more narrowly. Consequently, restraint advocates argue for reductions in U.S. forces in Europe on geopolitical and budgetary grounds, as noted above.

China-first advocates have similarly not built out detailed posture recommendations for U.S. forces in Europe. However, they have articulated the types of capabilities and trade-offs they would seek to bolster U.S. presence in the Indo-Pacific at the expense of U.S. posture in Europe. These trade-offs would result in major cuts to U.S. forces and capabilities in Europe that could significantly hinder NATO’s ability to deter Russian aggression. As one China-first advocate writes:

So long as China is our priority, the United States will be forced to withhold forces from Europe to deter or defeat Chinese aggression, even if Russia attacks NATO first. This will significantly limit our ability to help deter, deny, or repel a Russian assault because many of the capabilities required for a Taiwan contingency are also vital for Europe, including air and naval strike platforms; long-range missiles; air and missile defenses; intelligence, surveillance, and reconnaissance assets; and logistics forces.

According to this approach, force structure elements that would be removed or reduced from the United States’ current military posture in Europe for redeployment to the Indo-Pacific would include the two F-35 squadrons from RAF Lakenheath and at least some number of the six destroyers currently forward-stationed at Rota. In terms of ground forces, a China-first posture would similarly reduce long-range fires and theater air and missile defense assets to be prioritized for competition in the Indo-Pacific. Critical enablers — including airlift and aerial refueling, prepositioned stocks, and munitions stockpiles — would similarly be de-prioritized in the European theater.

A China-first approach to posture in Europe is thus willing to incur major risk and even potential military setbacks to field the needed capabilities and systems in the Indo-Pacific region. Accordingly, advocates call on NATO allies and partners in the European Union to take on a significantly greater burden in providing for their own defense. While a China-first posture in Europe may retain more U.S. forces relative to a restraint posture, such as ABCTs, China-first supporters are willing to divest those forces and units in a resource-constrained fiscal environment.

In addition to shifting current forces from Europe to the Indo-Pacific, China-first advocates also call for shifting force planning and security assistance efforts toward competition with China and the defense of Taiwan. They argue that procurement policy and the development of new capabilities should prioritize systems and capabilities for Indo-Pacific missions and the Taiwan contingency, such as surface ships, submarines, and precision-guided munitions. They also call for greater investments in improving the resilience of Indo-Pacific basing and infrastructure at the expense of similar investments in Europe. Advocates more forcefully argue against the security assistance currently provided to Ukraine in its war against Russia. They contend that this assistance, particularly of munitions, has at least two problems: it is contributing to dwindling U.S. stockpiles that could be used in a contingency with China, and munitions should instead be allocated to the defense of Taiwan.

Advocates of a China-first approach to strategy and posture generally recognize the high level of risk they are willing to incur in order to prioritize the Indo-Pacific and ensure that Taiwan does not fall to China. However, a Europe posture based on this strategy poses many of the same drawbacks as restraint. But the immediate shift in forces and capabilities from Europe to the Indo-Pacific associated with a China-first strategy poses much greater short-term risk in Europe, particularly if assistance to Ukraine is drastically reduced at the same time. The reduction in military aid vital to the Ukrainian war effort could allow the Russian military to gain the upper hand in the conflict, conquer all (or at least more) territory in Ukraine, encourage Russia to take military action elsewhere in Europe and other regions, and embolden China.

CONCLUSION

In short, any benefits of the three alternatives — extending the U.S. military’s current posture in Europe, restraint, or China-first — are outweighed by the costs and risks. As noted in Chapter 8, a significant withdrawal of U.S. forces along the lines of restraint or a China-first approach would jeopardize U.S. national security interests and significantly embolden authoritarian regimes in China, Russia, Iran, North Korea, and elsewhere.

PART III CONCLUSION

CH. 08

FINAL THOUGHTS

The U.S. military presence in Europe will likely remain contentious for several reasons. First, a substantial number of U.S. policymakers and analysts assess that China is the most significant threat to the United States for the foreseeable future and that the United States should focus the bulk of its military posture and attention — including its military air, naval, and maritime forces — in the Indo-Pacific. Second, some policymakers and analysts support decreasing the U.S. presence in Europe because European governments have generally failed to increase their defense budgets or focus on high-end military capabilities. Third, some contend that the United States should focus on problems at home, such as combatting immigration, improving health care, and stemming the production, trafficking, and use of such drugs as fentanyl. Fourth, still others assess that Russia poses little conventional or nuclear threat to the United States and its NATO allies in the short- or long-term.

There is validity in some of these points. China is a major threat, European governments need to spend more (and spend more effectively) on defense, and the United States needs to better address a wide range of challenges at home. As this report maintains, however, the United States has significant and enduring interests in Europe that will require a force posture of “forward defense.” A notable decline in the United States’ force posture in Europe would likely be significant and dangerous for U.S. national security in several ways.

First, it would embolden a revanchist Moscow and undermine deterrence in Europe. President Vladimir Putin and other Russian leaders would likely see a declining U.S. force posture in Europe as a sign of weakening U.S. resolve and potentially declining power. The United States’ limited response following Russia’s illegal annexation of Crimea in 2014 and military action in eastern Ukraine later that year likely encouraged Russia to take future action. Second, a deteriorating U.S. posture would likely embolden other U.S. adversaries, such as China, and heighten concerns among U.S. allies and partners in Asia about U.S. resolve. The views in Taipei, the most likely flashpoint with China, are striking. Some of Taiwan’s national security leaders have warned that a reduced U.S. commitment to Europe — including aid to Ukraine — would heighten Taiwanese concerns about U.S. resolve. Only 34 percent of those in Taiwan in 2023 believed that the United States is a trustworthy country, a decline of more than 11 percentage points from 2021. Researchers assessed that the drop was partly caused by a perception that U.S. resolve is weakening in Europe, including in Ukraine.

First, it would embolden a revanchist Moscow and undermine deterrence in Europe. President Vladimir Putin and other Russian leaders would likely see a declining U.S. force posture in Europe as a sign of weakening U.S. resolve and potentially declining power. The United States’ limited response following Russia’s illegal annexation of Crimea in 2014 and military action in eastern Ukraine later that year likely encouraged Russia to take future action. Second, a deteriorating U.S. posture would likely embolden other U.S. adversaries, such as China, and heighten concerns among U.S. allies and partners in Asia about U.S. resolve. The views in Taipei, the most likely flashpoint with China, are striking. Some of Taiwan’s national security leaders have warned that a reduced U.S. commitment to Europe — including aid to Ukraine — would heighten Taiwanese concerns about U.S. resolve.1 Only 34 percent of those in Taiwan in 2023 believed that the United States is a trustworthy country, a decline of more than 11 percentage points from 2021. Researchers assessed that the drop was partly caused by a perception that U.S. resolve is weakening in Europe, including in Ukraine.

PERSISTENT U.S. INTERESTS IN EUROPE

The United States has several enduring interests in Europe: protect the U.S. homeland and the security of the American people from threats based in Europe; promote and expand economic prosperity and opportunity; realize and defend the democratic values at the heart of the American way of life; and defend and support the United States’ European allies. As noted in more detail below, Russia will remain the most significant threat to Europe for the foreseeable future.

U.S. interests in Europe are likely to endure even with a U.S. focus on the Indo-Pacific and other regions. Based on these interests, the United States has several defense objectives in Europe:

• Deter and defeat conventional and nuclear-armed conflict directed against the U.S. homeland and U.S. allies, as well as coerce, persuade, and influence adversary behavior;

• Counter irregular and gray zone activities and compete effectively below the threshold of conventional conflict using both defensive and offensive means;

• Counter terrorist and other transnational threats;

• Deter and prevent state and non-state actors from acquiring, proliferating, or using weapons of mass destruction; and

• Maintain access to trade routes and global commons.

U.S. interests and defense objectives in Europe are based, to a great extent, on deterring a revanchist Russia. In the short term, NATO should be able to effectively deter a Russian conventional or nuclear attack against NATO territory, though Russia possesses significant irregular and gray zone capabilities. Over the next three to five years, however, the threat from Russia will likely increase. Moscow has the intentions and is developing the capabilities to threaten the United States, Europe, and their allies and partners.

Over the long run, there are several factors that could change the military balance in Europe. For example, the United States could become overstretched due to a major theater war against China in the Indo-Pacific. European conventional and logistical capabilities are limited — particularly for high-end war — which creates vulnerabilities if the United States were to withdraw significant air, naval, and even ground forces from the region. U.S. or European political will to develop robust military capabilities or strengthen NATO could also weaken, undermining deterrence.

Russia could rebuild its military capabilities over the next several years with help from China, Iran, North Korea, and other countries. Indeed, the speed of Russian military reconstitution will likely be impacted by help from China’s industrial base, as well as assistance from Iran, North Korea, and other countries. China has already provided several types of assistance to Russian defense firms, such as navigation equipment for M-17 military transport helicopters; jamming technology, such as telescoping antennas for military vehicles; parts for fighter jets; parts for radar units, which are used to detect enemy aircraft, missiles, and unmanned aircraft systems (UASs) as part of Russia’s S-400 anti-aircraft missile system; semiconductor chips for weapons systems; more than $12 million in UASs and UAS parts; and substantial aid to offset Western sanctions. As a 2023 U.S. intelligence report concluded, China “has also become an increasingly important buttress for Russia in its war effort” by “supplying Moscow with key technology and dual-use equipment used in Ukraine.”

In addition, Iran has provided several types of assistance to Russia, such as UASs, particularly the Shahed-136 precision-attack suicide drone; over 300,000 artillery shells and over 1 million rounds of ammunition; infrastructure, including helping to build a UAS factory in the Russian town of Yelabuga; and potentially ballistic missiles. Finally, North Korea has provided some military assistance, including artillery shells and other munitions, to Russia. Growing foreign assistance to Russia from China, Iran, and North Korea will help facilitate the reconstitution of its military.

DEVELOPING A POSTURE OF FORWARD DEFENSE

U.S. posture in Europe should be flexible enough to maintain deterrence but also allow some U.S. air and naval forces to surge to other regions — such as the Indo-Pacific — in case of contingencies. While this study does not conduct a global posture study, it assesses that the United States will likely need to deter two major adversaries, Russia and China. The United States should take several steps to enhance its posture in Europe over the next several years to strengthen deterrence and reassure its NATO allies in response to a Russia whose leaders are rebuilding their military and possess revanchist ambitions.

Ground: The United States should adopt a 4+2 posture beginning in 2025 that consists of four U.S. brigade combat teams (BCTs) and two headquarters, in Germany and Poland. This force posture would involve shifting from a rotational to a permanent armored brigade combat team (ABCT) in Poland to strengthen deterrence against a revanchist Russia. Overall, the United States should retain three permanent forward-stationed BCTs — one ABCT in Poland, one infantry brigade combat team (IBCT) in Italy, and one Stryker Brigade Combat Team (SBCT) in Germany — and one rotational IBCT headquartered in Romania. This model should include the permanent forward-basing of two combat aviation brigades. In addition, the United States should increase its long-range fires capabilities in Europe by facilitating further sales of systems, such as the High-Mobility Artillery Rocket System (HIMARS), to NATO allies. Finally, the U.S. military should increase efforts to build and enhance allied and partner special operations capabilities, with a focus on Eastern flank states, as part of forward defense.

Air: In terms of air combat capabilities, a forward defense posture recommends maintaining all seven forward-deployed fighter squadrons currently based in Europe and adding an additional F-16 squadron to Spangdahlem Air Base. Forward-deployed F-35 squadrons enhance the capabilities of U.S. and allied forces, given the aircraft’s ability to collect and transfer electronic data from adversary systems to provide greater situational awareness. In addition, this analysis recommends forward-stationing an additional F-16 squadron at Spangdahlem to provide greater short-term combat capacity as allied F-35 squadrons come online.

Maritime: The United States should continue its naval presence in the Baltic Sea region to deter Russian aggression and strengthen interoperability with allies and partners. In addition, the U.S. Navy should supplement existing NATO anti-submarine warfare capabilities by developing and deploying additional systems to the region. The United States should also expand its Arctic posture and capabilities to counter Russian and Chinese security interests. The U.S. Coast Guard could expand its icebreaking fleet with the procurement of three heavy Polar Security Cutters and three medium Arctic Security Cutters.

Prepositioned Equipment and Munitions Stockpiles: The United States should bolster its prepositioned equipment and munitions stocks in Europe to enhance the readiness of U.S. forces. While the Army Prepositioned Stock-2 has been somewhat augmented by funding from the European Deterrence Initiative, the Army should take additional steps to improve the readiness of this equipment and the forces overseeing it.

Intelligence, Surveillance, and Reconnaissance: The demand for U.S. ISR assets will only increase as the military expands missions and operations in the Indo-Pacific and the Russian military reconstitutes its capabilities on NATO’s eastern flank. While priority may be given to the Indo-Pacific, the Department of Defense (DOD) should maximize its available ISR assets for use by both U.S. European Command and U.S. Indo-Pacific Command. The DOD is currently seeking to modernize its ISR capabilities, with plans to retire the RQ-4 by FY 2027 and the MQ-9 by FY 2035. However, the DOD and the services must ensure that any gaps in ISR coverage are limited. This could be managed by timing the retirement of certain platforms to coincide with the activation of new assets. Alternatively, the DOD could leverage commercial capabilities to cover any gaps until requirements are established and new platforms come online. The Army is currently testing commercial assets in operations in Europe under its High Accuracy Detection and Exploitation System (HADES) to define the requirements for the replacement for the RC-12 Guardrail aircraft.

Integrated Air and Missile Defense: The United States should increase air and missile defense capabilities in Poland in coordination with a permanent ABCT in Poland. The Army should also prioritize the development and deployment of additional Patriot battalions. In terms of ballistic missile defense, the United States should maintain its current posture and force structure in line with Operation Atlantic Sentry. Relevant units include the six Aegis destroyers homeported in Rota, Spain, along with the two Aegis Ashore sites based in Romania and Poland.

Nuclear Posture: The United States should increase modernization efforts, exercises, and scheduled deployments of assets to the European theater to bolster its deterrent capabilities and reassure allies. This includes modernizing its gravity bombs with the new B61-12. The U.S. military and NATO should also continue to conduct exercises with nuclear-capable platforms, including Bomber Task Force missions, to enhance readiness and assure allies of U.S. support.

Cyber and Space: U.S. forces should continue to enhance the security and resilience of their cyber systems and networks while simultaneously assisting European partners and allies. U.S. Cyber Command (CYBERCOM) should deploy additional “hunt forward” teams to Europe to counter threats to U.S. forces and allies from Russia and Russian-backed groups. To capably resource further deployments and ensure readiness, CYBERCOM should also seek to expand the number of cyber mission teams across the services. The United States should also expand deployments of U.S. Space Force units and personnel to Europe. Space Force units can play a major role in supporting forward-deployed U.S. forces by preventing enemy interference and maintaining open lines of satellite communication.

Security Cooperation: The United States should focus on helping strengthen European military capabilities in such areas as combat support, including short-range air defense and long-range fires; airlift; heavy maneuver forces; maritime capabilities, including sensors and survivability systems; sufficient quantities of long-range precision strike weapons, such as long-range anti-ship missiles; and multi-spectrum ranges to train and maintain high-readiness forces. Security cooperation efforts should also involve additional security assistance, arms sales, training, partner capacity missions, and strategic coordination between the United States, NATO, and European states on the development of forces and capabilities.

Europe remains a vital region for the United States. The last two U.S. national security and national defense strategies have prioritized China as the main global threat. But Russia’s brutal invasion of Ukraine, continuing aggression, and growing cooperation with China are stark reminders that the United States has significant and enduring interests in Europe as well.

Seth G. Jones is senior vice president, Harold Brown Chair, director of the International Security Program, and director of the Transnational Threats Project at the Center for Strategic and International Studies (CSIS). He focuses on defense strategy, military operations, force posture, and irregular warfare. He leads a bipartisan team of over 50 resident staff and an extensive network of non-resident affiliates dedicated to providing independent strategic insights and policy solutions that shape national security.

Seamus P. Daniels is a fellow for Defense Budget Analysis in the International Security Program at CSIS, where he researches issues related to defense funding, force structure, and military readiness.

Catrina Doxsee is a fellow with the Transnational Threats Project at CSIS, where she analyzes international and domestic terrorism and the irregular activities of countries such as Russia, China, and Iran. Outside of CSIS, she is a member of the editorial board for the Irregular Warfare Initiative at the Modern War Institute at West Point.

Daniel Fata is the president of Fata Advisory LLC. He is a public policy expert, national security consultant, and strategic adviser focused on helping companies and organizations enhance their product and program offerings through the development of comprehensive government affairs strategies, risk assessments, strategic planning, and advocacy initiatives.

Kathleen McInnis is a senior fellow and director of the Smart Women, Smart Power Initiative at CSIS. Her research areas include the intersection of gender and national security; global security strategy; defense policy; and transatlantic security.