I plan to produce a book-length manuscript that analyzes the sources of national economic conflict and cooperation in U.S.-Japan relations. Existing explanations in both the academic and policy literature emphasize the very different internal characteristics and structures - political, economic, and cultural -- of the two countries. My project begins instead with the external sources of economic conflict: the international security and economic environments within which Japan and the United States interact. I will examine the U.S.-Japan relationship across four time periods, each of which is characterized by a different combination of international economic and security conditions. I intend the study to contribute to our understanding of the relationship between international and domestic politics, to the integration of political economy and security studies in international relations theory, and to the ongoing policy debate over how to alleviate conflict in U.S.-Japan relations.