Is European Rearmament Feasible? Key Developments, Limitations, and Policy Implications

Sungwon Lee

sw.lee@sejong.org​

Research Fellow

Sejong Institute

1. Problem Statement

❍ ​Europe is currently confronted with existential and multilayered challenges in the context of a reconfigured international order and a rapidly evolving security environment.

- The entrenched reliance on external defense support since the end of World War II has gradually eroded Europe’s autonomous capacity to respond to security threats.

- The outbreak of the Russia–Ukraine war has clearly exposed structural vulnerabilities in Europe’s defense ecosystem, including its industrial infrastructure, technological self-reliance, production capacity, and the resilience of its supply chains.

❍ ​As geopolitical tensions and technological competition among major powers such as the United States, Russia, and China continue to escalate, Europe is increasingly constrained in its ability to maintain competitiveness and secure sustainable drivers of growth across key sectors, including energy, the defense industry, and digital infrastructure.

❍ ​In particular, under the second Trump administration, U.S. engagement, long regarded as the cornerstone of European security, has been steadily diminishing, accompanied by growing uncertainty over the reliability and sustainability of the alliance and collective defense frameworks Europe has long relied upon.

❍​ Facing heightened concerns over Europe’s security posture, countries across the region have begun introducing fragmented and parallel strategies to strengthen their respective defense capabilities. The debate on rearmament gained further momentum following the European Commission President’s announcement of the “ReArm Europe” initiative in March.

❍​ Certain perspectives have assessed Europe’s ongoing rearmament as a shift in its security paradigm. In Korea, however, divergent conceptual interpretations and fragmented outlooks on this development continue to emerge, underscoring the need for a more comprehensive and systematic approach to analysis.

2. Underlying Drivers of European Rearmament

A. The Russia-Ukraine War and the Vulnerabilities of Europe’s Defense Architecture

❍ ​Over more than three years of direct and indirect involvement in the Russia-Ukraine war, Europe has revealed structural vulnerabilities across its defense ecosystem, including inefficient force maintenance, inadequate weapons production and supply, a fragmented defense industry, a lack of technological self-sufficiency, bureaucratic institutions and regulations, and insufficient investment. These shortcomings have exposed the limits of Europe’s capacity to conduct systematic and rapid military operations.

B. Trump’s Second Term: Deepening Rifts in the Transatlantic Alliance and Growing Security Gaps

❍ ​The Russia-Ukraine war, which erupted during a period marked by accelerating shifts in the balance of power among major powers and a strategic realignment of the global security order after the end of the Cold War, served as a turning point for Europe to recognize the reality that the U.S. security umbrella, which it had previously relied upon, could no longer be sustained at the same level and in the same manner as before.

- Since the outbreak of the Russia-Ukraine war, disagreements and tensions among NATO member states have been intensifying over asymmetries in responsibilities and cost-sharing between the United States and European members, as well as over approaches to carrying out security missions, raising questions about the sustainability of NATO’s identity and role.

❍ ​In particular, during the second Trump administration, a series of strategies pursued under the “America First” doctrine have led to a relative decline in regional engagement, contributing to a deepening security vacuum in Europe.

C. Marginalization in the process of negotiating a ceasefire agreement in the Russia-Ukraine war

❍​ Ceasefire negotiations in the Russia-Ukraine war have primarily taken the form of bilateral talks led by the United States with Russia and with Ukraine, during which Europe has shown signs of being marginalized in the process.

❍​ Despite being within the direct and indirect sphere of impact of the war, Europe has lacked meaningful influence in the process of negotiating detailed terms for a ceasefire and the establishment of peace, and is now faced with the task of developing its own measures to ensure sustainable peace in the post-ceasefire period.

3. Directions and Key Areas

A. Direction of 'European Rearmament'

❍​ European rearmament refers to a set of policies and strategies aimed at reducing security dependence on external actors, particularly the United States, in response to existential threats such as the Russia-Ukraine war. It encompasses efforts to strengthen independent military capabilities and defense systems in order to achieve strategic autonomy.

❍​ European rearmament is unfolding in a multi-layered and simultaneous manner, encompassing efforts to enhance defense capabilities at the national level, within NATO, and through the EU, as well as initiatives to establish a regional nuclear deterrence community in Europe.

(1) Efforts to enhance defense capabilities at the individual national level

❍​ Since the outbreak of the Russia-Ukraine war, European countries have accelerated rearmament efforts through increased defense spending, weapons acquisition and development, and the restructuring and expansion of their defense industries. These moves are regarded as the most significant military buildup since the end of the Cold War.

(2) Defense enhancement measures at the NATO level

❍​ NATO continues to serve as the central pillar of Europe’s collective defense and a key platform with integrated operational capabilities, and discussions on enhancing defense capabilities are ongoing within the NATO framework.

❍​ At the NATO Defense Ministers’ Meeting held in June, the criteria for increased defense spending and military capability enhancement required of member states were outlined through the “Capability Targets 2025.”

❍​ In the context of shifting geopolitical dynamics, Europe’s approach to NATO rests on two fundamental premises: enhancing strategic autonomy and maintaining complementarity.

❍​ In the 10th EU-NATO Progress Report published in June, Europe reaffirmed that its ongoing efforts to enhance strategic autonomy at the EU level, including increased defense spending, addressing capability gaps, expanding defense industrial capacity, and strengthening defense production, must be pursued within the framework of shared threat perceptions and a complementary partnership with NATO.

(3) Initiatives for developing a Europe‑wide nuclear deterrence community

❍​ Within the discourse on European rearmament, the establishment of a nuclear deterrence capability at the European level has emerged as a central pillar. Centered around France, this initiative aims to reduce structural dependence on U.S. extended deterrence and to strengthen regional defense capabilities against the nuclear threat posed by Russia.

❍​ At present, France’s nuclear umbrella is widely viewed as having limitations as a full alternative to U.S. extended deterrence, due to its high costs, operational complexity in political and technical terms, and questions regarding its credibility. The prevailing assessment is that it could serve only a limited complementary function in the event of a reduced U.S. security commitment.

(4) Efforts to Enhance Defense Capabilities at the EU Level

❍​ The EU has presented a multi-layered set of strategies and implementation plans aimed at enhancing the efficiency and sustainability of financial and military support for Ukraine, while simultaneously strengthening defense capabilities within Europe. These efforts are intended to boost the competitiveness of the defense industry and reinforce overall readiness.

❍​ Although the various strategic documents being released in parallel across Europe may appear fragmented, they are, in the broader context, being organized into the following phased structure:

① Threat assessment and defense vision → ② Implementation plans for strengthening defense capabilities → ③ Securing financial resources and reinforcing the defense industrial ecosystem → ④ Institutional and strategic proposals for long-term security integration

    B. Core Agendas of European (EU-Level) Rearmament (ReArm Europe Plan / Readiness 2030)

    ❍​ The European rearmament plan has been detailed in The White Paper for European Defence – Readiness 2030, which outlines the primary threats currently identified by Europe, strategic priorities for enhancing defense capabilities, and large-scale investment and financial plans aimed at securing credible deterrence and integrated defense capacity.

      -Objectives outlined in The White Paper for European Defence – Readiness 2030: reduction of structural dependence on external security providers such as the United States, enhancement of defense industry competitiveness and narrowing of technological gaps, strengthening of security in Eastern Europe through support for Ukraine, expansion of defense investment and advancement of financial innovation, and establishment of a complementary cooperation framework with NATO and global partners.

   4. Constraints and Risk Factors

  ❍​ European rearmament is grounded in an optimistic outlook that it can lead to enhanced defense capabilities by deterring potential threats from Russia, improving burden-sharing within the transatlantic alliance, and strengthening defense industry and technological capacity.

  ❍​ Despite the optimistic outlook, Europe’s rearmament plans face a range of constraints and risks, raising concerns about the limits of feasibility and the potential for negative spillover effects.

     A. Constraints on Rearmament

(1) Inefficiency and Closed Nature of Europe’s Defense Industrial Ecosystem

❍​ In the absence of existential threats since the Second World War, Europe has maintained a posture of disarmament, leading to the downsizing of weapons production infrastructure and the erosion of its capacity to supply essential stockpiles for wartime operations.

(2) Sustainability of Rearmament Funding and Expenditure

❍​ The White Paper for European Defence – Readiness 2030, released in March, reveals a structural limitation in that it relies entirely on the national budgets of individual member states without direct public financing at the EU level. This raises concerns about the long-term sustainability of funding and the stability of defense expenditures.

(3) Technological Gap and Structural Dependence on Great Powers (the United States)

❍​ While various analyses have addressed the question of whether Europe can replace the strategic role of the United States, growing structural dependence on the U.S. in advanced technological domains suggests that increased defense spending or the strengthening of conventional forces alone is insufficient to fundamentally reduce Europe’s defense reliance on the United States.

(4) Underdeveloped Political Consensus Among European States

❍​ European rearmament has emerged as a clear trend at the macro level, yet political consensus among member states remains insufficient with respect to its necessity, objectives, and degree of implementation.

(5) Legal Constraints on Rearmament (European Armed Forces)

❍​ The scope and operational framework of rearmament at the EU level face complex legal and institutional constraints. In some cases, establishing an integrated defense system among member states may require high-level institutional measures, including constitutional amendments.

❍​ Unlike NATO, the EU lacks a permanent, institutionalized defense mechanism with structured operational guidelines, command architecture, and force deployment capabilities, and its member states have not yet developed the capacity to conduct large-scale joint military operations.

      B. Risks Associated with Rearmament

(1) Possibility of an Arms Race and the Undermining of Regional Stability

❍​ Europe’s rearmament, driven by a strong perception of threat from Russia, is being pursued with a clear focus on increasing defense spending and enhancing combat capabilities, while institutional efforts to establish risk management mechanisms remain limited.

(2) Deteriorating Fiscal Soundness and Fragmentation of Military Capabilities in Europe

❍​ Although the EU’s loan scheme was designed as a supplementary instrument to promote defense integration through joint projects among member states, uncertainty remains as to how many countries will voluntarily make use of it.

❍​ In the absence of a shared EU-level public finance framework, individual countries’ independent increases in defense spending may, in the short term, contribute to the growth of the defense industry and the revitalization of national defense markets, yet in the medium to long term, such measures could lead to widening fiscal deficits and rising national debt, ultimately undermining the overall fiscal soundness of Europe.

❍​ Currently, the level of increased defense spending across European countries varies significantly depending on each state's debt level and fiscal capacity, and it remains unclear whether such individual increases are meaningfully contributing to the enhancement of the EU’s collective defense capabilities.

(3) Overlapping Roles and Competitive Dynamics between NATO and the EU

❍​ The EU and NATO have traditionally maintained a complementary relationship by dividing responsibilities between the political-economic domain and territorial defense, but since the late 1990s, the EU’s development of its own defense policy has led to increasing overlap and deepening of functional roles with NATO.

❍​ Given the increasing complexity and sophistication of modern security threats, overlapping roles should not necessarily be viewed negatively. From the perspective of establishing a multi-layered defense structure, the EU’s expanded defense initiatives may be seen as an evolution of cooperation, as they have enabled complementary financial and industrial contributions to NATO’s operational capabilities.

❍​ Nonetheless, at the core of the EU’s rearmament policy lies a growing awareness of the need to secure 'strategic autonomy' by reducing its structural dependence on NATO, a goal that inherently presents an existential dilemma of enhancing European independence without creating rifts with NATO

   5. Conclusion and Policy Implications

    ❍​ Europe’s rearmament efforts have inevitably emerged as a strategic response to the shifting security landscape and growing geopolitical uncertainty, yielding both positive and negative outcomes.

   ❍​ Europe’s current rearmament initiatives clearly face limitations, but they are not expected to represent a fully developed model at this stage. Instead, the gradual accumulation of ongoing multidimensional capability-building efforts will be a decisive factor in shaping the future transformation of the European security paradigm.

   ❍​ If Europe can clearly identify both the opportunities and challenges arising from its rearmament process and adopt a strategic approach that ensures the balanced advancement of sustainable defense capabilities and integration, it may progressively solidify its strategic autonomy.

A. Clear Goal-Setting for Rearmament, Identification of Priority Areas, and Political Consensus

❍​ The key to ensuring sustainability lies in defense planning that transcends national interests, balanced investment, and the advancement of joint defense initiatives based on political consensus.

❍​ Rearmament based on fragmented national defense efforts may ultimately remain a declarative commitment, hindering the achievement of genuine strategic autonomy and integration at the

❍​ European level, while exacerbating division and disconnection among member states.

❍​ Europe’s case carries important implications for South Korea’s efforts to bolster self-reliant defense capabilities in the face of complex external threats and demographic challenges.

❍​ Discussions on establishing a collective security architecture, such as an Asia-Pacific version of NATO, are also unfolding in Northeast Asia; however, as demonstrated by the course of Europe's rearmament efforts, the core of any collective security initiative must begin with concrete dialogue and political consensus on the object of deterrence, shared security interests, and the means of achieving them.

 B. The Necessity of Strengthening Complementarity and Credibility in the ROK–U.S. Alliance

  ❍ ​Europe’s current security crisis stems from having outsourced regional security for an extended period, which has led to the deterioration of its defense ecosystem, the emergence of asymmetric alliance dynamics, and increased vulnerability to political shifts.

  ❍​ Similar to Europe, South Korea is compelled to enhance its self-reliant defense capabilities in the face of complex security challenges, while grappling with the dilemma that such efforts may conflict with the strategic priorities of its alliance.

  ❍​ Future issues related to defense autonomy, including increased defense spending, the transfer of wartime operational control, and adjustments to the size and role of U.S. Forces Korea, are not merely matters of financial investment. They represent a fundamental transformation that requires the establishment of a strategic defense culture and structural reform. To minimize potential conflicts of values and interests between allies, careful and deliberate policy coordination is essential.

  ❍​ South Korea needs to reinforce extended deterrence through strategic consultations with the United States and, under the new administration, maintain close strategic communication on evolving bilateral security initiatives to steadily enhance its defense capabilities and adjust its role within the alliance.

   C. Directions for Defense Industry Cooperation with Europe in the Context of Rearmament

  ❍​ Since the outbreak of the Russia–Ukraine war, major European countries, particularly those bordering Russia, have increasingly taken note of South Korea’s defense technology and production capabilities, creating new opportunities for the growth of the South Korean defense industry.

  ❍​ Despite quantitative growth, South Korea's expansion in the European defense market has largely ridden the wave of short-term demand driven by the Russia–Ukraine war, relying heavily on the export of finished products to a limited number of countries with immediate needs. As a result, structural limitations remain in securing long-term competitiveness in the defense industry.

  ❍​ NATO has promoted deeper cooperation with the IP4 countries in pursuit of enhanced interoperability with allies and partners, broader access to open markets, and the diversification of supply chains. In contrast, the EU’s current rearmament efforts are focused on strengthening strategic autonomy by preventing technology leakage, protecting the internal market, and advancing monetary and industrial self-sufficiency.

  ❍​ South Korea needs a region-specific strategic approach that can effectively leverage the limited avenues for cooperation in response to changes in Europe’s security environment and shifts in policy direction.

  ❍​ There is still demand for the export of complete conventional weapons systems, but in the medium to long term, a transition is required toward partnership-based cooperation models, including the establishment of local production bases for technology-intensive defense materials, technology exchange and transfer, joint R&D, and supply chain integration.

  ❍​ In addition, efforts should be made to diversify defense export hubs not only in Europe but also in the Middle East and the Asia-Pacific region.

   D. Diplomatic Engagement in Crisis Management

  ❍​ In the context of the Russia–Ukraine war, Europe’s rearmament has been driven primarily by military responses, with relatively less emphasis placed on crisis management and diplomatic solutions.

  ❍​ Northeast Asia is facing a complex security environment, marked by North Korea’s nuclear and missile threats, rising tensions in the Taiwan Strait, and strategic competition between the United States and China.

  ❍​ It is essential for South Korea to strengthen cooperative networks with regional partners in response to shared threats, such as Korea–U.S. and Korea–U.S.–Japan cooperation, in order to establish a multilayered security architecture.

  ❍​ At the same time, it is necessary to actively utilize dialogue platforms for crisis management and to pursue diplomatic efforts aimed at deterring potential threats and preventing conflicts.

  ❍​ South Korea should pursue defense enhancement, technological capacity building, the reinforcement of alliance-based deterrence, and diplomatic efforts for crisis management in a parallel and integrated manner.