Evolution of Japanese security policy and the House of Councilors

Abstract Japanese security policy has undergone a significant degree of evolution since the early 1990s. As a result, the range of responses Japan can make in international crisis has significantly expanded. The gradual evolution and expansion of the Japanese security policy culminated in the legislation of security-related bills under the second Abe administration in September 2015. The security-related bills dramatically transformed Japanese security policy as it allowed Japan to exercise the right of collective defense when certain conditions are met. The gradual change of Japanese security policy has so far gathered much academic attention. There is a strong claim in the existing literature on Japanese security policy that changes in security policies became possible because of reforms in domestic institutions, which had expanded the Japanese prime minister's power. It is the contention of this article that the Japanese prime minister is still faced with severe constraints from the Diet, in particular from the House of Councilors even after a series of institutional reforms has empowered Japanese prime ministers to significantly alter Japanese security policy. It demonstrates that as the House of Councilors has significant power in the Japanese political system, some Japanese prime ministers had to have the implementation of some security policies delayed or was driven to revise some policies they had originally envisioned through several case studies.