Japan's new politics challenge some basic assumptions about U.S.-Japan alliance management. From the election of the Democratic Party of Japan (DPJ) in 2009 to the return of the Liberal Democratic Party (LDP) in 2012, this new era of alternating parties in power has revealed the growing importance of Japan's domestic politics in shaping alliance cooperation. The fluidity in electoral outcomes in recent parliamentary elections reveals the extent of Japanese voter frustration with the government. A divided Diet challenged the Japanese government's ability to implement policy. Policy reform is in high demand in Tokyo, and the U.S.-Japan alliance is not immune to the popular call for greater accountability as past choices are increasingly subjected to policy review.

Beyond partisan differences over how to manage the alliance, Japan's new politics have deeper implications for the U.S.-Japan alliance. CFR Senior Fellow Sheila A. Smith identifies three challenges that will confront U.S. policymakers as they seek to work with Japanese governments in the years ahead. First, electoral change will continue to create hurdles for predictable alliance management. Second, the challenges of alliance management should not be attributed solely to one party, but rather to the more complex domestic sensitivities to the complicated geostrategic shifts underway in the Asia-Pacific region. Finally, the United States and Japan must address the complex normative challenge to the alliance as national identity debates across Asia challenge the postwar order and recast domestic politics in Japan.