The convergent evolution of nuclear strategy: the ROK and Japan's differing paths to nuclear hedging

Abstract

This study investigates how and why the Republic of Korea (ROK) and Japan have adopted similar nuclear hedging strategies since 2016 despite their contrasting political environments and technological capabilities. Focusing on enrichment and reprocessing (ENR) capabilities and delivery systems-the most critical components of nuclear latency-this study examines the level of nuclear potential in both South Korea and Japan. Additionally, to assess another key factor in nuclear hedging strategies, namely political will, this research explores the domestic political environments and policy debates in both countries. Historically, the ROK has avoided discussions on nuclear armament since the Cold War. However, since 2016, as North Korea's nuclear threat has intensified and U.S. security commitments have weakened, public support for nuclear armament has grown. In response, the ROK policymakers have actively engaged in discussions to enhance the country's nuclear latency. In contrast, many Japanese elites emphasize the importance of nuclear latency, which appears to stem from Japan's government structure, which is less influenced by public opinion. Japanese elites advocate for enhancing nuclear capabilities. Furthermore, regarding delivery systems-another crucial component of nuclear latency alongside ENR-the ROK possesses a more diverse and advanced system compared to Japan. This research contributes to scholarly discussions on nuclear proliferation, U.S.-East Asia relations, alliance politics, and regional security in East Asia. The comparative analysis also sheds light on the complex interplay between technological capabilities, historical legacies, and normative frameworks in shaping nuclear strategies to counter nuclear threats in the region.