The Treaty of San Francisco formally ended Japan’s state of war with most Allied countries on 28 April 1952.
The treaty was signed in San Francisco on 8 September 1951 by Japan and 48 countries, including the United States and many other wartime Allies. It restored Japan’s sovereignty and established the postwar legal framework between Japan and the signatory powers.
The treaty did not take effect on the day of the 1945 surrender ceremony. Japan’s military capitulation ended wartime fighting, but the Allied occupation continued and the legal peace settlement required years of negotiation. The treaty entered into force on 28 April 1952, ending the occupation and formally ending the state of war with its participating signatories.
The Soviet Union signed neither the treaty nor the later peace arrangement with Japan. Japan and the Soviet Union instead normalized relations through the Soviet–Japanese Joint Declaration of 1956, which formally ended their state of war but did not settle every territorial dispute.