The emphasis on ‘new ways of warfare’ in the Defense of Japan 2026, released on 4 August, indicates Japan’s desire to play a more assertive role. However, the emphasis on US primacy raises questions of policy independence. The document also unveils tensions between automation and staffing, as well as between excessive self-reliance and positive international cooperation in defence technology. As Prime Minister Sanae Takaichi attempts to bring Japan closer to the US while bolstering native defence capabilities, the 2026 edition conveys both the prospects and challenges inherent in her quest.

Japan’s Minister of Defence Shinjiro Koizumi released the 2026 edition of his ministry’s flagship white paper, ‘Defense of Japan 2026’, on 4 August.[1] The 598-page 2026 edition, currently available in unabridged form only in Japanese,[2] provides an opportunity to measure incremental changes in Japanese strategic policy and its responses to changes in the strategic environment.

The current edition is especially significant as the first to be released under Prime Minister Sanae Takaichi, whose longstanding advocacy of a more active Japanese role in regional security is well known. Her assumption of office in 2025 preceded the rapid and substantial deterioration in relations with China (largely due to her off-the-cuff remarks on Taiwan during a Diet session in November 2025), growing tensions with Russia and continued anxiety over the Democratic People’s Republic of Korea (DPRK).

Meanwhile, US President Donald Trump, by overturning decades-long patterns of Japanese over-reliance on US security guarantees, strengthened Takaichi’s efforts to break free of Japan’s post-war pacifism and attain a measure of self-reliance. The current edition of the white paper deserves attention as a milestone laying out the contours of Japan’s emerging response to the changing security situation.

Japan’s Threat Perception

As Part 1 of the white paper makes clear, Japan sees itself in a hostile neighbourhood. ‘The Greatest Trial of the Postwar Era’ is, according to it, a product of unilateral attempts to change the status quo by ‘[s]tates that do not share universal values or political and economic systems based on such values’, balance-of-power contestation between the leading states, ‘[r]apid developments in science and technology’ and the emergence of activities below the threshold of belligerence.[3] The return of interstate war also exercises the drafters of the white paper to some extent, with Russia’s 2022 invasion of Ukraine attracting particular attention.[4]

Regionally, the white paper clearly identifies China as the ‘unprecedented and the greatest strategic challenge’ for Japan. Among the reasons listed, one immediately notes the not-insignificant space accorded to concerns about Taiwan.[5] While the level of detail is understandable given the Taiwan Strait’s importance to Japanese strategists, the language appears to serve three additional purposes.

Firstly, it seems to be driving and legitimising the ‘Taiwan panic’ currently prevalent in Japanese policymaking circles, whereby a sense of proprietorial concern for the self-ruled island’s welfare in its own right is implied. Secondly, and not unrelatedly, the white paper’s discursive emphasis seems to be doing the domestic political work of substantiating Prime Minister Takaichi’s comments on Taiwan in November 2025, translating them into policy. Thirdly, the language on Taiwan seems designed to convey opposition to China’s goals, especially in the section that comments on Beijing’s stance.

The DPRK ‘pose[s] an even more grave and imminent threat to Japan’s national security than ever before’ through its ‘military activities’, a significant elevation of Japan’s threat perception level.[6]........

© IDSA