The European Centre for Strategic Studies and Policy (ECSAP)
For more than seven decades, European security has rested upon a fundamental strategic assumption: that the United States would remain the continent’s ultimate security guarantor through NATO. This transatlantic arrangement shaped Europe’s defence planning, military investments, political priorities, and strategic culture throughout the Cold War and well into the twenty-first century. However, geopolitical developments over the past several years have begun to challenge that assumption. Growing political debates in Washington regarding the future costs of European defence, combined with shifting American strategic priorities toward the Indo-Pacific and intensifying competition with China, have forced European governments to confront an increasingly uncomfortable question: can Europe guarantee its own security if American military commitments gradually diminish?
The debate is no longer theoretical. Russia’s prolonged war against Ukraine, increasing military activity across NATO’s eastern flank, expanding cyber threats, instability in the Middle East, and renewed competition in the Arctic have collectively transformed the European security environment. At the same time, several European governments have announced unprecedented increases in defence spending, while discussions surrounding strategic autonomy, common procurement, and the future role of European defence industries have accelerated. The issue is no longer whether Europe should assume greater responsibility for its own security, but whether it possesses the political cohesion, industrial capacity, financial resources, and military capabilities required to do so.
This paper argues that Europe has entered a historic transition in which strategic autonomy should not be interpreted as replacing NATO or distancing itself from the United States. Rather, it should be understood as strengthening Europe’s ability to act independently whenever necessary while preserving the transatlantic alliance as the cornerstone of collective defence. The future credibility of European security will increasingly depend upon the continent’s willingness to transform political ambition into sustainable military capability.
The European security order is undergoing its most profound transformation since the collapse of the Soviet Union. For decades, most European governments operated within a strategic environment in which American military superiority guaranteed deterrence against external aggression. Defence planning therefore emphasized multinational cooperation within NATO while allowing many European states to reduce military expenditure and prioritize economic integration, social welfare, and political cooperation.
That strategic model is now under unprecedented pressure. Russia’s full-scale invasion of Ukraine fundamentally altered European threat perceptions, demonstrating that large-scale conventional warfare remains a central feature of international politics. Simultaneously, the United States has increasingly redirected military and diplomatic attention toward the Indo-Pacific, where strategic competition with China has become Washington’s principal foreign policy priority. These parallel developments have generated growing concern among European policymakers regarding the long-term sustainability of the continent’s dependence upon American military leadership.
As a result, debates surrounding European strategic autonomy have shifted from academic discussions into practical policymaking. Questions that once appeared politically sensitive—including common defence procurement, integrated command structures, expanded European defence industries, and increased military spending—have moved to the centre of European security planning. Whether Europe can transform these ambitions into operational capability will shape not only the future of NATO but also the geopolitical balance of power across the international system.
Why Europe Is Rearming Again
The resurgence of defence as a political priority across Europe is not the product of a single geopolitical event, but rather the culmination of several interconnected crises that have fundamentally altered the continent’s strategic environment. Russia’s invasion of Ukraine shattered long-held assumptions that large-scale interstate warfare had become a relic of the twentieth century. At the same time, instability in the Middle East, repeated cyberattacks targeting European infrastructure, sabotage incidents affecting critical energy networks, growing tensions in the Arctic, and intensifying strategic competition between the United States and China have collectively demonstrated that Europe faces a far more volatile security environment than policymakers anticipated only a decade ago.
This changing landscape has forced governments to reassess decades of defence policy that prioritized economic efficiency over military preparedness. Throughout much of the post-Cold War period, many European states significantly reduced military spending, downsized armed forces, and increasingly relied on American military capabilities to guarantee collective defence through NATO. Defence industries contracted, ammunition production declined, and military procurement slowed as governments redirected public resources toward welfare systems, infrastructure, healthcare, and economic modernization. While this approach reflected the relatively stable geopolitical environment of the time, it also created structural weaknesses that have become increasingly apparent since 2022.
The prolonged conflict in Ukraine has exposed serious limitations within European defence readiness. Stockpiles of ammunition have been depleted at unprecedented rates, defence industries have struggled to expand production quickly, and military planners have recognized that many European armed forces lack the logistical depth required for sustained high-intensity operations. These shortcomings have accelerated an unprecedented wave of defence investment across the continent. Countries that historically maintained modest military budgets have announced substantial increases in defence expenditure, while several governments have launched long-term modernization programmes aimed at rebuilding capabilities that had gradually disappeared over previous decades.
Importantly, European rearmament is not simply about purchasing additional military equipment. It reflects a broader recognition that security has become inseparable from economic resilience, industrial capacity, technological innovation, and political cohesion. Defence policy is increasingly integrated with industrial strategy, research and development, cybersecurity, space capabilities, and critical infrastructure protection. This multidimensional approach represents one of the most significant transformations in European strategic thinking since the end of the Cold War.
The Limits of European Dependence on NATO
For more than seventy-five years, NATO has served as the cornerstone of European security. The Alliance successfully deterred Soviet expansion during the Cold War, managed numerous post-Cold War security challenges, and continues to provide the institutional framework through which European and North American allies coordinate collective defence. Nevertheless, the evolving international security environment has prompted growing discussion regarding the long-term sustainability of Europe’s heavy dependence on American military leadership.
Although the United States remains NATO’s strongest military power, successive American administrations have increasingly emphasized that European allies must assume greater responsibility for their own defence. This expectation reflects both financial considerations and shifting geopolitical priorities. As Washington devotes greater attention to strategic competition with China in the Indo-Pacific, European policymakers recognize that future American military resources may become increasingly divided between multiple global theatres. This does not necessarily imply a reduction in American commitment to NATO, but it does suggest that Europe can no longer assume unlimited access to American military capabilities during every future crisis.
The debate surrounding burden-sharing has therefore become one of the defining issues within the transatlantic relationship. While many European governments have significantly increased defence budgets since Russia’s invasion of Ukraine, substantial disparities remain between national capabilities. Some member states continue to rely heavily upon American intelligence, strategic airlift, missile defence, command-and-control systems, and logistical support. Reducing these dependencies will require sustained investment over many years, together with greater political coordination among European governments.
This challenge extends beyond military spending alone. Strategic autonomy requires Europe to develop independent capabilities across defence manufacturing, technological innovation, intelligence collection, cyber resilience, and critical supply chains. Building these capabilities demands long-term political commitment, institutional reform, and significant financial investment. Consequently, strengthening European defence should not be interpreted as weakening NATO. Rather, a more capable Europe would enhance the Alliance by sharing greater responsibility for collective security while allowing the United States greater strategic flexibility in addressing global challenges beyond the European continent.
Can Europe Build a Genuine Defence Union?
One of the most significant strategic questions facing the European Union concerns whether closer military cooperation can evolve into a genuinely integrated European defence capability. For decades, proposals for deeper defence integration encountered political resistance arising from concerns over national sovereignty, differing strategic cultures, and varying perceptions of security threats. The changing geopolitical environment, however, has significantly altered these calculations.
Recent years have witnessed unprecedented progress in joint defence procurement, military mobility, intelligence cooperation, and collaborative research projects. European governments increasingly recognize that fragmented procurement systems generate unnecessary costs, reduce interoperability, and weaken the competitiveness of the European defence industry. Coordinated investment offers opportunities to strengthen industrial capacity while reducing duplication across national armed forces.
Nevertheless, substantial obstacles remain. Defence policy continues to be closely linked to national sovereignty, making governments reluctant to transfer ultimate decision-making authority over military operations to supranational institutions. Differences in defence spending, operational priorities, and constitutional frameworks further complicate integration efforts. Eastern European member states often prioritize deterrence against Russia, while southern members focus more heavily on instability across North Africa and the Mediterranean. Reconciling these diverse strategic priorities represents one of the greatest challenges facing any future European Defence Union.
Despite these difficulties, incremental integration appears increasingly likely. Rather than replacing national armed forces, future European defence cooperation will probably evolve through expanded joint procurement programmes, coordinated industrial investment, integrated logistics, common training, intelligence sharing, and enhanced interoperability. Such an approach would strengthen Europe’s collective capabilities while preserving national political control over military decision-making. In this sense, the future European Defence Union may emerge less as a centralized military institution and more as a highly integrated network of national capabilities operating within a common strategic framework.
Europe’s Defence Industry: From Strategic Weakness to Industrial Revival
One of the most profound consequences of Europe’s renewed focus on defence has been the recognition that military power ultimately depends upon industrial capacity. The war in Ukraine exposed significant weaknesses in Europe’s ability to sustain prolonged military operations, particularly regarding ammunition production, missile manufacturing, armoured vehicles, air defence systems, and critical defence technologies. Decades of reduced procurement, fragmented industrial policies, and limited production capacity left many European countries unable to replenish military stockpiles at the pace required by modern warfare. As a result, defence industrial policy has become a central component of Europe’s broader security strategy.
Across the European Union, governments are now investing heavily in expanding production facilities, supporting defence innovation, and strengthening cooperation between public institutions and private industry. Major defence manufacturers are increasing investment in new production lines, while smaller technology firms are becoming increasingly involved in artificial intelligence, autonomous systems, cybersecurity, quantum technologies, and advanced battlefield communications. Defence is no longer viewed solely as a military expenditure but increasingly as a strategic investment capable of supporting technological innovation, industrial competitiveness, and economic growth.
At the same time, European policymakers face the challenge of balancing national industrial interests with the need for greater integration. Individual governments naturally seek to protect domestic defence industries, yet fragmented procurement reduces efficiency and increases costs. The development of a more integrated European defence industrial base will therefore require greater political coordination, standardized procurement procedures, and long-term investment strategies capable of providing industry with predictable demand. Without such reforms, Europe risks continuing to rely on external suppliers for critical military capabilities, undermining its ambitions for greater strategic autonomy.
The revitalization of Europe’s defence industry also carries broader geopolitical implications. A stronger industrial base would enable Europe not only to improve its own military readiness but also to support partners through defence exports, joint production programmes, and technological cooperation. In an increasingly competitive international environment, industrial capacity has become an essential element of geopolitical influence, allowing states to convert economic strength into strategic resilience.
Strategic Autonomy Without Strategic Separation
Perhaps the greatest misconception surrounding European strategic autonomy is the assumption that it implies political or military separation from the United States. In reality, the concept has evolved considerably over recent years. European leaders increasingly emphasize that strategic autonomy should be understood as the ability to act independently when necessary rather than the desire to replace NATO or weaken the transatlantic partnership.
This distinction is particularly important given the continuing importance of American military capabilities for European security. The United States remains indispensable in areas including strategic intelligence, missile defence, nuclear deterrence, space capabilities, global logistics, and advanced military technologies. Europe is unlikely to replicate these capabilities fully in the foreseeable future. Nevertheless, reducing excessive dependence in selected areas would strengthen both European security and the Alliance as a whole by creating a more balanced distribution of responsibilities.
Greater European capability would also provide political flexibility during future crises. Situations may arise in which European security interests require rapid action even if American strategic priorities lie elsewhere. In such circumstances, stronger European military capabilities would enhance collective deterrence while preserving the credibility of NATO. Strategic autonomy therefore complements rather than contradicts transatlantic cooperation.
The future relationship between Europe and the United States should consequently be viewed as an evolving partnership rather than a zero-sum choice between dependence and independence. A stronger Europe is likely to become a more valuable ally for Washington while simultaneously increasing the continent’s capacity to safeguard its own security interests within an increasingly multipolar international system.
The European Union should continue implementing a long-term defence strategy that integrates military modernization with industrial policy, technological innovation, and economic resilience. Defence spending should be accompanied by sustained investment in domestic production capabilities, advanced research, cyber resilience, artificial intelligence, and emerging technologies that will define future military competition.
European governments should accelerate joint procurement programmes in order to reduce fragmentation and strengthen interoperability among national armed forces. Common investment in ammunition production, missile systems, air defence, unmanned platforms, and military mobility would enhance operational readiness while reducing unnecessary duplication of resources. Greater coordination between governments and the private sector should also be encouraged to strengthen Europe’s defence industrial base and improve supply chain resilience.
At the institutional level, cooperation between NATO and the European Union should continue expanding across areas such as intelligence sharing, cybersecurity, infrastructure protection, hybrid threat response, and military mobility. Rather than creating competing security structures, European initiatives should reinforce the Alliance by enabling European members to assume greater responsibility for regional defence.
Finally, policymakers should recognize that defence resilience extends beyond military capabilities alone. Economic stability, technological leadership, energy security, secure digital infrastructure, and societal resilience all contribute directly to Europe’s long-term security. Defence policy should therefore be integrated within a broader strategy designed to strengthen Europe’s overall strategic competitiveness.
Europe is entering a defining moment in its post-Cold War history. The assumptions that shaped the continent’s security architecture for more than three decades are being fundamentally reconsidered as geopolitical competition intensifies and traditional patterns of international cooperation evolve. The central challenge facing European leaders is no longer whether greater defence investment is necessary, but how to transform increased spending into sustainable military capability, industrial resilience, and long-term strategic credibility.
Russia’s war against Ukraine, instability across Europe’s southern neighbourhood, expanding cyber threats, growing competition in the Arctic, and uncertainty regarding future American strategic priorities have collectively demonstrated that European security can no longer rely upon assumptions formed during a different geopolitical era. The continent must adapt to an international environment characterized by simultaneous military, technological, economic, and political competition.
Building a more capable European defence architecture will require patience, political consensus, and sustained investment extending well beyond individual electoral cycles. Success will depend upon Europe’s ability to modernize its armed forces, strengthen its defence industries, improve technological competitiveness, deepen cooperation among member states, and maintain the transatlantic alliance as the cornerstone of collective security while assuming greater responsibility for its own defence.
Ultimately, Europe’s defence debate is not simply about military spending or institutional reform. It is about the future role of Europe in an increasingly uncertain world. Whether the continent emerges as a stronger and more autonomous strategic actor will shape not only the future of NATO but also the balance of power across the international system for decades to come. The decisions taken during the remainder of this decade may therefore prove to be among the most consequential in the history of European security integration since the end of the Cold War.
