Japan on the road to remilitarization

For the first time since the end of the Second World War, Japan has formally signalled through its annual defence white paper that it is prepared to remilitarise in response to what it describes as an increasingly complex and dangerous regional environment.

The document, Defense of Japan 2026, marks a clear departure from the post-war constraints that confined Tokyo largely to a defensive posture. Under Prime Minister Sanae Takaichi and Defence Minister Shinjiro Koizumi, the 598-page paper frames the current period as a “new era of crisis” and the most severe security environment Japan has faced since 1945.

The white paper positions the country not merely as a self-defence force but as a more assertive military actor ready to engage in the emerging strategic contest across the Asia-Pacific.

This shift carries heavy historical weight. Many communities across Asia still carry living memories of Japanese occupation and wartime atrocities. Survivors remain, and collective memory has not faded. For ASEAN states in particular, Japan’s move requires careful recalibration of relationships in a region that is no longer defined solely by the United States and China. India, Russia, both Koreas and others are also asserting greater roles. The old binary is giving way to a more crowded and fluid strategic landscape.

The white paper organises Japan’s concerns around three main pillars;

First is the threat assessment. China is explicitly labelled Japan’s “greatest strategic challenge.” Tokyo highlights Beijing’s military expansion beyond the First Island Chain into the deeper Pacific and cites concrete incidents, including a late-2025 radar-locking episode against a Japanese aircraft. North Korea is described as a grave and imminent threat due to its continuing missile tests. Russia’s deepening military cooperation with Pyongyang, alongside joint Sino-Russian operations, further darkens the picture. The neighbourhood, in Japan’s view, has become a severe and multi-layered threat matrix.

Second is the recognition of a “new way of warfare.” For the first time the document dedicates substantial attention to unmanned systems. Lessons drawn from the war in Ukraine have prompted heavy emphasis on autonomous vehicles and drones. Japan is developing a defensive drone swarm network called “Shield,” intended to reduce personnel risk while improving response times. Multi-domain integration is also prioritized.

Artificial intelligence for situational awareness, cyber defence, cognitive operations and electromagnetic warfare. The traditional Self-Defence Forces model is being reshaped around technology that blurs the line between defence and more offensive potential.

Third comes the concrete rearmament agenda. Defence spending for fiscal year 2026 has surpassed 9 trillion yen and is progressing toward the 2 percent of GDP target. The domestic defence industry has been elevated to a strategic priority. Lethal-arms export restrictions are being loosened and transnational research and development encouraged. Beyond the foundational alliance with the United States, Japan is accelerating military networks with Australia, the Philippines, NATO partners and a revitalised defence relationship with South Korea.

Japan sees the need to rely less upon the US

Japan is no longer content to rely solely on bilateral dependence on Washington. The white paper outlines a multilayered approach. The U.S.–Japan–South Korea trilateral focuses on real-time missile-warning data sharing and joint exercises, driven by the North Korean threat. Relations between Takaichi and South Korean President Lee Jae Myung have enabled more practical contingency planning despite persistent historical and territorial friction. In the Indo-Pacific, Japan is building quasi-alliances. With Australia, cooperation includes joint exercises and critical minerals, while Japanese firms compete for major defence contracts. With the Philippines, a Reciprocal Access Agreement and Official Security Assistance are delivering coastal radar and maritime surveillance assets aimed at countering Chinese maritime pressure.

Further afield, Tokyo insists that Euro-Atlantic and Indo-Pacific security are inseparable. Ties with NATO are being formalised in cyber, space and cognitive domains. Lessons and intelligence from Ukraine, particularly regarding North Korean weapons and drone warfare, are feeding back into Japan’s own force modernisation. On the industrial front, Japan is co-developing a next-generation stealth fighter with the United Kingdom and Italy under the Global Combat Air Programme and working with the United States on glide-phase interceptors against hypersonic threats.