‘All Politics is Local’: the US–China Balance in the First Island Chain and Japan’s Defense Transformation

This article examines recent changes in Japan’s security policy, visible in its 2022 Japan National Security Strategy. It finds that the underlying driver for Japan’s military investments is a new abandonment fear centred around the perceived loss of U.S. local military dominance. China’s A2/AD buildup has increased the cost for U.S. forces to operate in the First Island Chain, undermining U.S. defence commitment to Japan. Tokyo is investing in capabilities to address local capability gaps and demonstrate its commitment to the alliance. This article’s findings highlight two aspects of balance of threat theory not explicitly theorised by Walt: (1) the importance of considering the balance between the alliance as a whole and the threat, and (2) the need to distinguish between local-theatre and strategic-level deterrence.