Sailors from USS Curtis Wilbur (DDG-54) approach the Japan Maritime Self-Defense Force’s (JMSDF) Hyuga-class helicopter destroyer JS Hyuga (DDH-181) on a rigid-hull inflatable boat alongside the Republic of Korea’s forces on Sept. 15, 2025. US Navy photo

Jordan Jang | February 21, 2026

Introduction

The North Atlantic Treaty Organization (NATO) is regarded as the gold standard of collective defense. It rests on a strong legal framework, which not only codifies mutual defense but also creates obligations binding member states. Yet this assumption mistakes historically specific conditions for necessity. In 2026, NATO may no longer be the model for collective defense in international law but rather the exception.

Military exercises such as Operation Freedom Edge, conducted by the United States, Republic of Korea, and Japan, illustrate a thinner yet still lawful model of security cooperation. Multilateral military exercises lack permanent command structures or a standalone treaty dictating cooperation. Rather, they rely on bilateral treaties, host-state consent, and the sheer grit of military personnel on sea, air, and land. While Operation Freedom Edge may lack the collective action treaty articles that bind NATO states, this absence does not reflect its weakness. Instead, multilateral military exercises like Freedom Edge reflect an appropriate response to political uncertainty and region-specific security concerns in the status quo. 

Can the NATO Framework Last? 

The North Atlantic Treaty of 1949 created an unprecedented alliance that went beyond the minimum requirements of collective self-defense under international law. Few alliances before or since have replicated this level of institutionalization. NATO’s design reflected a unique convergence of states facing a singular adversary, relatively homogeneous political and legal cultures, and the availability of sustained U.S. military and economic support.

Article V’s mutual defense clause is well known, but increasing attention has been paid to Article III, which commits member states to “maintain and develop their individual and collective capacity to resist armed attack.” The extent to which states must “maintain and develop” their security capacities has become a subject of renewed scrutiny. Although Article III does not specify quantitative benchmarks, the 2025 NATO Summit in The Hague gave this provision a numerical definition when NATO allies agreed to raise defense spending to five percent of GDP by 2035. Article III thus reflects NATO’s expectation of sustained national investment in collective defense. However, as debates over burden-sharing once again become a contentious issue, Article III underscores both NATO’s strength and its vulnerability. Allies may once again agree to increased spending, but a treaty framework premised on continuous material commitment may prove difficult to sustain in an era increasingly defined by strategic autonomy.

In a world order in which the United States no longer consistently plays the role of the world’s police, the availability of U.S. military support inevitably comes into question. As recent discussions in Davos have revealed, world leaders increasingly anticipate a global order oriented toward strategic autonomy—not only through the restructuring of supply chains, but also through the expansion of independent military capabilities. There is little doubt that NATO remains the predominant alliance binding many democratic Western states. Nevertheless, a growing emphasis on autonomy, even while preserving traditional alliances, will shape how security cooperation is structured going forward. Against this backdrop and considering renewed U.S. concerns that NATO allies disproportionately benefit from American military commitments, future alliance models may look less to NATO’s treaty-bound framework and more to flexible, practice-based arrangements such as Operation Freedom Edge.

Freedom Edge: An Alliance Without Obligations 

Operation Freedom Edge exemplifies a different approach to collective defense cooperation. As its name suggests, a military exercise at this scale requires close operational coordination among three countries’ militaries. Yet it relies on no defense treaty, no standing headquarters, or no permanent joint command. Unlike NATO, participation does not create obligations. Instead, its legality is grounded in bilateral mutual defense treaties (US-South Korea, US-Japan), trilateral consent, and the right of collective self-defense recognized in Article 51 of the UN Charter.

By relying on preexisting bilateral arrangements and general principles of international law, Freedom Edge avoids the formalization and institutionalization associated with treaty-based alliances. At the same time, it enables meaningful cooperation across domains—including maritime security, air defense, and information-sharing—without requiring states to assume new obligations toward one another. In contrast to NATO’s Article V, participation in Freedom Edge preserves full sovereign discretion over whether, when, and how collective defense would be exercised.

Joint military exercises such as Freedom Edge further perform important strategic functions. Repeated exercises give participating states the necessary practice in simulating how collective self-defense should be understood and operationalized in practice. Over time, they establish shared expectations regarding coordination, interoperability, and response thresholds, reducing uncertainty without locking states into permanent commitments. In this sense, exercises lead to cooperation, signal alignment, and prepare states for coordinated action, all while remaining formally outside a formal treaty framework like NATO.

Compared to NATO’s institutional constraints, such as Article III’s emphasis on sustained material commitment, Freedom Edge represents an adaptive alternative. Where NATO demands long-term political consensus and resource investment, multilateral exercises like Freedom Edge enables states to exercise autonomy funding and operating their militaries while maintaining traditional alliances. Routine exercises like Freedom Edge circumvent the burden-sharing debate. This shows that collective defense in 2026 may increasingly be structured through action rather than obligation—through practice rather than permanence.

A Brief Note on QUAD 

Perhaps Japan’s leadership in advancing the Quadrilateral Security Dialogue (Quad) can be read as an effort to construct an Indo-Pacific analogue to NATO. Yet such a reading overlooks the structural and legal realities of the region. The Indo-Pacific security environment is geographically expansive, politically heterogeneous, and strategically asymmetric—conditions that sit uneasily with NATO-style institutionalization. Hence, unlike NATO, the Quad rests on no treaty, no mutual defense clause, and maintains no standing command or permanent decision-making body. Analysts accordingly characterize the Quad not as a collective defense alliance, but as a coordination framework designed to facilitate strategic convergence without binding legal commitments. This institutional thinness reflects a resistance to NATO’s treaty-bound model by participating states and a preference for flexible cooperation. 

Conclusion

NATO remains powerful, but it may be the exception for 21st-century collective defense. Evidence of this shift can be seen in Operation Freedom Edge and the trilateral cooperation among the United States, South Korea, and Japan over the past two years.