Japan’s Proactive Pacifism and Defense Budget Expansion Amid Regional Threat Perceptions

Background: Japan's unprecedented defense budget increases and acquisition of counterstrike capabilities under its revised National Security Strategy adopted in late 2022, with continued implementation through 2023 and 2024, mark a significant departure from postwar pacifist defense norms amid escalating regional security concerns involving China and North Korea. Aims/objectives: This study examines the diplomatic and domestic political processes underpinning Japan's defense policy transformation and its implications for regional alliance dynamics. Method: A qualitative analysis of Japanese defense white papers, parliamentary debates, and interviews with security policy specialists was conducted covering the strategy's adoption and subsequent implementation period. Results: Findings indicate that domestic public support for defense expansion increased substantially following heightened regional threat perceptions, while regional reactions varied considerably, with South Korea expressing cautious support amid improving bilateral relations and China characterizing the shift as destabilizing remilitarization. Trilateral coordination with the United States and South Korea deepened significantly during the period under review. Conclusion: The research concludes that Japan's defense transformation represents a durable recalibration of its security posture rather than a temporary response to immediate threats. Sustained trilateral coordination and transparent communication regarding defense intentions are recommended to manage regional perceptions while pursuing legitimate security modernization objectives consistent with Japan's evolving strategic environment and alliance commitments.

Keywords: Japan defense policy, proactive pacifism, regional security, alliance coordination, Indo-Pacific strategy