Germany and Japan's New Security Roles in a Changing Strategic Environment

For much of the post-war era, Germany and Japan represented a distinctive model of international influence. Unlike traditional great powers, both countries built their global roles less around military strength and more around economic capacity, diplomatic engagement, technological leadership, and support for international institutions. This approach was shaped by the political and historical consequences of the Second World War, which created lasting constraints on the role of military power. In Germany, the legacy of militarism produced a strategic culture centred on civilian control, multilateralism, and alliance-based security. In Japan, constitutional limitations and public attitudes toward the use of force created one of the world’s most restrained defence postures.

The strategic environment that allowed Germany and Japan to maintain limited military roles has fundamentally changed. For Germany, Russia’s invasion of Ukraine marked a decisive turning point (Zeitenwende). For decades, Berlin operated under the assumption that major conventional conflict in Europe was increasingly unlikely, allowing successive governments to prioritise economic influence, diplomatic engagement, and institutional integration while accepting relatively limited defence investment. The return of interstate conflict has challenged those assumptions and forced Germany to reconsider the relationship between economic strength and strategic responsibility. The debate is no longer simply about whether Germany should increase military spending, but about what obligations accompany its position as Europe’s largest economy and one of its most influential political actors.

This transition represents a serious shift in German strategic thinking. The challenge lies in determining how a country historically cautious about the use of force can contribute more actively to collective security without treating military rebuilding as an end in itself. Germany is increasingly confronted with the task of reconciling two ideas that have often been viewed as contradictory: maintaining restraint while also developing credible deterrence. The transformation represents less a rejection of Germany’s post-war identity than an attempt to redefine what that identity requires in a more dangerous security environment.

Japan faces a similar dilemma but within a different regional context. Its strategic reassessment has been shaped by China’s expanding military capabilities, growing competition in the Indo-Pacific, tensions surrounding the East China Sea, and uncertainty surrounding a potential Taiwan crisis. These pressures have been compounded by North Korea’s advancing missile and nuclear programmes and wider concerns about regional stability. Japan’s response reflects a growing recognition that economic power alone may no longer be sufficient in a region facing increasing security competition. Interpreting Japan’s transformation as a simple return to military power overlooks the continued importance of constitutional constraints, domestic political debate, and public sensitivity toward the use of force. Japan’s defence reforms remain framed around deterrence, alliance cooperation, and national defence rather than traditional power projection.

One important dimension of change in both Germany and Japan is a broader redefinition of responsibility among leading democratic states, with expanded defence capabilities emerging as one expression of this transformation. During the post-war period, restraint itself became a source of legitimacy. Germany and Japan demonstrated that influence could be achieved through economic development, diplomacy, and support for international institutions rather than through military instruments. Their experiences suggested that influential democratic states could play significant international roles while maintaining strict limits on the use of force

The current security environment has challenged the assumption that economic and diplomatic influence alone are sufficient to preserve international stability. A state may support an international order politically but maintaining that order may also require the ability to deter actors willing to undermine it. This has created a difficult transition for countries whose identities were partly built around avoiding traditional military roles. The emerging model therefore reflects a different understanding of strategic responsibility, in which stronger defence capabilities are viewed as a means of preserving democratic institutions and international stability rather than weakening them.

Much of the debate surrounding Germany and Japan focuses on whether increased defence spending represents militarisation. However, this distinction requires greater precision. Military preparedness involves developing capabilities intended to respond to security challenges, while militarisation refers to a broader process in which military institutions, strategic thinking, and security priorities increasingly shape political life and national identity. This distinction is important because contemporary developments in both countries are taking place within strong democratic and institutional frameworks. Defence policy remains subject to civilian control, parliamentary oversight, public debate, and international commitments, and neither country is seeking to separate itself from the broader systems of cooperation that have shaped its post-war development.

This does not mean concerns are absent. Expanding military capabilities can generate domestic political disagreements, contribute to regional suspicion, and create security dilemmas in which one state’s defensive measures are interpreted as threatening by others. Stronger capabilities do not automatically produce greater security. The challenge for both Germany and Japan is therefore maintaining a balance between developing sufficient capabilities to respond to genuine threats while preventing security concerns from redefining national identity around military power.

A defining feature of contemporary developments in Germany and Japan is the role of alliances. Unlike historical examples of military expansion, their current defence transformations are embedded within existing security structures. Germany’s reforms are closely connected to the North Atlantic Treaty Organization (NATO) and European collective defence, with the objective of strengthening shared security rather than developing an independent sphere of influence. As Chancellor Friedrich Merz stated ahead of an EU leaders’ summit, ‘we are strengthening the European NATO nations; we are reinforcing NATO’s European pillar’, reflecting Germany’s emphasis on strengthening NATO’s collective defence framework rather than pursuing strategic autonomy outside existing alliances.

This alliance-based approach changes the meaning of military power. For Germany and Japan, defence capabilities are increasingly understood as contributions to maintaining a wider security order as opposed to instruments of national dominance. Their experiences reflect a broader trend among democracies facing similar pressures, including renewed great-power competition, cyber threats, technological rivalry, supply-chain vulnerabilities, and uncertainty over the future direction of the international system. Germany and Japan are therefore not isolated cases. They represent part of a larger reassessment among states that had previously relied on a relatively stable international environment and are now confronting a world in which security concerns have returned to the centre of foreign policy.

The evolution of Germany and Japan illuminates a broader question for the future of democratic power: how states shaped by histories of destruction can transform the meaning of strength from an instrument of force into a commitment to responsibility and stability. Both countries are moving beyond the assumption that strategic responsibility requires limited defence involvement. Despite these changes, neither appears to be abandoning the institutional and political lessons that shaped the post-war era. Their challenge is finding a middle ground between vulnerability caused by insufficient preparedness and a model of security in which military power becomes central to national identity.

The transformation underway in Germany and Japan is therefore not a rejection of the past, but an attempt to reinterpret its lessons in a changing world. Their future security policies will not be measured only by defence budgets or military capabilities, but by whether they can demonstrate that stronger security roles can coexist with democratic restraint, institutional accountability, and a continued commitment to international cooperation.

Scott N. Romaniuk, Senior Research Fellow, Centre for Contemporary Asia Studies, Corvinus Institute for Advanced Studies (CIAS); Department of International Relations, Institute of Global Studies, Corvinus University of Budapest, Hungary.