By Li Hai
Japan has placed growing emphasis on alliance-building in recent years. It has steadily deepened a security cooperation network centered on the Japan-US alliance and extending to multilateral frameworks, in an effort to offset its shortcomings in long-range strike capabilities, power projection, and global situational awareness.
The Japan-US alliance has shifted from a model in which the US provided unilateral protection to Japan to one featuring joint forward deployment and proactive intervention. In 2015, Japan passed new security legislation that lifted the ban on the exercise of the right of collective self-defense, allowing it to use force in support of allies even when its home territory is not under direct attack. In 2024, the US and Japan substantially updated the US-Japan Security Treaty, upgrading their bilateral relationship from a defensive alliance to a military alliance that is both offensive and defensive. In pursuit of its so-called Indo-Pacific Strategy and to reduce the costs of maintaining hegemony, the US has continued to loosen restrictions on Japan's military development while pressing Tokyo to assume greater defense responsibilities.
Japan has also worked in coordination with the US to build a Japan-US Plus security cooperation network, expanding the reach and scope of its alliance system. Through this framework, Japan has established "2+2" dialogue mechanisms with multiple countries and international organizations in and beyond the region, and signed a series of defense cooperation agreements, including the Agreement on the Security of Information, the Reciprocal Access Agreements, and so on. These arrangements have steadily strengthened Japan's defense interactions with so-called like-minded countries.
Such bilateral and multilateral defense cooperation has enabled Japan to expand its influence and operational freedom simultaneously in both traditional military domains and emerging fields such as outer space and cyberspace. In addition, Japan is seeking to join the Pillar 2 of the AUKUS security alliance, which covers advanced and emerging military capabilities, including artificial intelligence, cybersecurity, quantum computing, and hypersonic technologies.
In order to revitalize its domestic defense industrial chain and test the performance of its equipment, Japan has deliberately loosened and strengthened its arms export policies, expanding its overseas defense market. To date, Japan has signed the Agreement Concerning the Transfer of Defense Equipment and Technology with 16 countries. Introduced in 2023, the Official Security Assistance (OSA) program has become an important instrument for Japan to expand defense partnerships.
According to Japan's Ministry of Foreign Affairs, the proposed budget for fiscal year 2026 will increase OSA funding from 8.1 billion yen in 2025 to 18.1 billion yen, more than doubling the previous level. The program's coverage has been expanded to include key countries in the so-called Indo-Pacific region, such as Thailand, Sri Lanka, and Timor-Leste, forming an arc-shaped layout together with previously included countries, including the Philippines, Indonesia, and Malaysia. The scope of assistance has continued to expand, now covering radar systems, patrol vessels, satellite communication systems, long-endurance unmanned aerial vehicles, and dual-use port facilities. Of particular concern is that Japan's Official Development Assistance (ODA) program, which has long served as an instrument of its foreign policy, has also seen its fiscal year 2026 budget tilt markedly toward Southeast Asia and Pacific Island countries, with funding for conducting information warfare with foreign countries rising by as much as 21.6%.
The various "small-clique" military cooperation mechanisms that Japan has participated in and promoted are highly targeted in nature. They not only intensify regional arms competition but also fuel bloc confrontation in the style of a new Cold War.