Administrative Structure To accomplish the aims of the occupation, the fmal terms proclaimed at the Potsdam Declaration on July 26, 1945, the Allies—the United States, the United Kingdom, China, and the Soviet Union—agreed to a joint occupation of Japan, once it surrendered. However, because of its predominant role in the fmal stages of the war against Japan in the Pacific, the United States took the lead in the occupation of Japan. Immediately, the United States planned to call for 600,000 troops and anticipated that this would include 315,000 American, 135,000 British Commonwealth, 60,000 Chinese, and 175,000 Soviet troops, all under the U.S. command. Yet, these numbers were later revised, and neither the Soviets nor the Chinese ever contributed forces after all. So, in the end, only the countries of the British Commonwealth shared occupation responsibilities with the United States by providing with 45,000 troops.
https://scholarworks.umt.edu/cgi/viewcontent.cgi?article=3123&context=etd
Theodore Cohen, Remaking Japan: The American Occupation as New Deal, New York, The Free Press, 1987, p.60.
波茨坦協議的計劃是各國派出兵力在美國指揮下實行對日本的占領,而不是像德國一樣劃成四片由四國來分治。