Signing of the Japanese Instrument of Surrender on September 2, 1945 had formally ended the most destructive and bloody war in the history of mankind. Even before that a new balance of power on the international arena began to form, that would persist for almost half a century. At the same time, it was obvious from the outright that the Allies had very different views on how the post-war world order should look like. Traditionally, both Russian and foreign academic literature focused on their disputes regarding the German question. This paper provides a brief overview of the US Department of State planning and recommendation process for the post-war reconstruction of Japan in 1939–1945, which had eventually led to the formation of the socalled San Francisco subsystem of international relations. The first section of the paper outlines the challenges faced by the State Department when it came to planning the post-war architecture of the Far East. In that regard, the author pays particular attention to the staff shortage, which forced the Department of State to strengthen partnership with private research organizations and involve them in long-term planning.The author emphasizes that if before the United States entered the war the US planners adopted a rather tough stance on Japan, after the attack on Pearl Harbor their approaches paradoxically changed. The second section examines the contradictions and tensions between those politicians and experts who believed that in the establishment of the post-war order in the Far East the US should cooperate with China, and those who promoted rapprochement with Japan. These groups were unofficially referred to as the ‘Chinese team’ and the ‘Japanese crowd’ accordingly. The paper shows that as the end of the war approached, these contradictions gradually faded into the background. The needs to promote the interdepartmental cooperation and to reconcile the positions of the State Department, the Military and Naval Ministries on the future of Japan came to the fore. This work resulted in a series of memoranda, which laid the foundation for the US post-war policy towards Japan. In conclusion the author provides a general assessment of the strategic decision-making process in the United States during wartime and emphasizes its consistency, thoroughness and flexibility. As a result, it enabled the US to achieve what seemed impossible: to turn Japan from an ardent adversary of the United States in the Pacific into one of its most reliable allies, and it remains such today.