Japan’s recent wave of defense diplomacy Manila has Jakarta, Canberra has Wellington – has raised familiar concerns about the country’s peace commitments. Critics warn of a slippery slope toward remilitarization. Yet this framework gives a fundamentally misinterpretation of what Tokyo is actually doing. Seen clearly, Japan’s defense equipment transfers represent something more modest in military terms and more significant in strategic terms: the deliberate construction of a network of cooperation among middle powers anchored in shared weapons supply chains.
The scale of Japan’s defense buildup, while remarkable by its own postwar standards, remains far short of what would qualify as militarization by any comparative measure. European middle powers such as France, Germany and the United Kingdom have long maintained arms export industries and military capabilities that dwarf Japan’s emerging position. The April 2026 Cabinet decision to remove the long-standing “five categories” restriction on exports of lethal weapons has domestic consequences – but it does not make Japan a major military power. This opens the door to another type of strategic contribution: becoming a supplier and partner within a regional defense ecosystem.
Soeya Yoshihide, professor emeritus at Keio University in Tokyo, made this distinction with unusual clarity. Japan’s postwar diplomacy, he argues, has always reflected a multilateral, middle-power orientation. The current arms export program must therefore be understood from this same perspective. The real logic is not deterrence through unilateral military buildup, but the creation of shared weapons supply chains among Asian middle powers – strengthening interoperability, mutual dependence and strategic alignment through common platforms.
This distinction is extremely important for how Japan defines its approach to potential partners. The idea of a Chinese containment could resonate with the Philippines, which is engaged in a direct confrontation with Beijing over the South China Sea. But it fails – or worse, triggers resistance – in Jakarta. Indonesia, like India, is seeking strategic autonomy between Washington and Beijing. Telling Indonesia that Japanese frigates or submarines will help contain China is frankly counterproductive.
The most compelling argument is that of regional supply chain integration: participation in a shared defense industrial network improves Indonesia’s capabilities and autonomy, while strengthening the collective resilience of middle powers in the Indo-Pacific. Jakarta signed a defense cooperation agreement with Tokyo in May 2026, and Indonesian navy officials have openly acknowledged their interest in Japanese frigates and submarines – but on Indonesia’s own terms, not as a junior partner in an anti-China coalition.
The most compelling evidence for this “medium energy supply chain” thesis is the emerging story around Japan’s upgraded Mogami-class frigate, known in Japan as 06FFM or “New FFM.” Australia has chosen the platform as its future multi-purpose frigate, with 11 ships planned and the first three to be built in Japan.
On May 7, New Zealand has identified the same frigate – alongside the British Type 31 – as a finalist in its own replacement programme. Wellington’s interest is not limited to hardware specifications. It reflects the logic of operating alongside partners on common platforms: shared parts, shared logistics, shared maintenance, shared training and ultimately shared operational resilience during crises.
If New Zealand chooses the new FFM, Japan’s vision of a shared maritime network among middle powers would begin to take concrete form. Japan would operate 12 Mogami-class and 12 New FFMs. Australia would commission 11 new FFMs. New Zealand would add at least two. More than 37 ships across three navies in the Indo-Pacific could ultimately share a family of common platforms.
Chief Cabinet Secretary Kihara Minoru described the potential selection as strengthening trilateral interoperability between Japan, Australia and New Zealand, while Defense Minister Koizumi Shinjiro framed the broader model – Australia, New Zealand, Philippines – as giving concrete shape to a free and open Indo-Pacific in terms of defense.
It is the language of cooperation between middle powers rather than that of traditional rivalry between great powers.
The case of the Philippines illustrates the practical dimension. Tokyo and Manila agreed in May 2026 establishing a working group for the potential transfer of Abukuma-class destroyer escorts – a move that could become Japan’s first export of lethal military equipment under the revised framework and an early test for its emerging defense strategy for middle powers.
Underlying all this is a second, less openly discussed factor: uncertainty about the United States itself. Japanese policymakers are acutely aware that Washington’s long-term strategic reliability cannot be taken for granted – a concern sometimes discussed privately as “Trump risk.” The Trump administration’s “America First” foreign policy, with its transactional approach to alliances and selective engagement with regional contingencies, has prompted Tokyo and its partners to protect themselves by deepening horizontal ties between them.
It is true that the Japanese-American alliance remains the cornerstone of Tokyo’s security policy. But many states in the region increasingly see Washington-centered alliances as insufficient at a time of geopolitical volatility. As a result, countries like Japan and Australia are strengthening horizontal ties among regional middle powers, thereby building a resilience that can complement – rather than replace – the alliance system.
In this sense, the medium energy supply chain program serves a dual purpose: strengthening collective capabilities against external coercion while reducing excessive dependence on a single customer.
Of course, obstacles remain. Japan still lacks the mature export infrastructure – long-term maintenance systems, technology transfer frameworks, industrial participation agreements and overseas support networks – that European defense exporters have developed over decades. Strengthening these capacities will itself require sustained institutional adaptation.
Messaging also remains tricky. The framework that works in Manila might not work in Jakarta. Overemphasizing anti-China deterrence risks alienating Southeast Asian states that prefer strategic ambiguity and diplomatic balance.
Yet the broader strategic opportunity is real.
Many middle powers in the Indo-Pacific – including Australia, New Zealand, the Philippines, Indonesia and Vietnam – share an interest in preserving a stable, rules-based regional order, even if they differ in how they wish to confront China. Japan’s emerging offer is not simply about selling weapons or building an Asian NATO. Rather, it is about becoming the anchor of a shared defense industrial ecosystem that improves interoperability, strengthens supply chain resilience, and deepens long-term strategic interdependence among regional partners.
This is an offer that many countries can accept on their own terms.
Postwar Japanese diplomacy has always functioned best within multilateral frameworks and cooperative networks. Properly understood, the evolution of Tokyo’s defense export policy does not constitute a break with this tradition, but an extension of it in the field of security. Japan’s ability to build such a network of middle powers may determine not only its future security role, but also the broader strategic architecture of the Indo-Pacific itself.