Security Cooperation Between Japan and South Korea on the North Korean Nuclear Threat: Strategic Priorities and Historical Issues*

This article examines the dynamics of Japanese-South Korean (ROK) relations regarding the North Korean nuclear threat, under the Park Geun-hye and Shinzo Abe governments. In particular, it explores how security cooperation between Japan and South Korea differed following the third and fourth North Korean nuclear threats. In contrast to existing explanations, this article focuses on the convergence and divergence of strategic priorities between the two countries, apart from external threat perception. This article contends that the credibility of the US commitment to protect its allies is a constant, regarding the increasing North Korean nuclear threat. Therefore, it is not considered a defining factor in Japan-ROK relations. Finally, cooperation and conflict over historical issues influence security relations between the two countries, but they are not constant variables. This article argues that the convergence/divergence interactions in strategic priorities, and the degree of discord and cooperation in historical issues between the two nations, determine the levels of security cooperation between Japan and South Korea.