At a time when security and political relations between the United States and Japan are exhibiting renewed confidence and strength, this study provides a timely analysis and reassessment of the early Cold War’s trans-Pacific bilateral alliance. Taking issue with studies that have characterized the United States as largely dismissive of Japanese national interests, the book reveals an engaged and pragmatic leadership working to develop an active partnership with America's former adversary. Drawing on the latest scholarship in both Japan and the United States, exhaustively reassessing the diplomatic record, and relying on a wealth of newly released archival material, the author offers a reinterpretation of key issues in the early Cold War relationship. The work also casts dramatic new light on Japan's importance as a target of covert diplomacy and Soviet espionage—and the significance, in this context, of Japan's internal conflict between progressive and conservative values and the wider debate over national identity and political legitimacy.