National sovereignty can be a hotly contested site. Usually contestation is between a national government and external parties such as other national governments or international bodies, or between a national government and internal bodies seeking a new state through a separatist movement. This chapter discusses another contested aspect of national sovereignty that receives little attention, where the contest is within the nation, between national and subnational government. The conservatism that dominated Japan’s local politics in early post-war changed significantly from the late 1960s with the election of progressive chief executives to head SNGs in many urban and metropolitan areas. Peace is a palpable concern for many Japanese citizens who remember and/or hope to prevent repeat of Japan’s experience as vanquished nation in 1945.