Which treaty formally ended the state of war between Japan and the Allied powers in 1952?

The Treaty of San Francisco formally ended the state of war between Japan and the Allied powers in 1952.

Japan’s military surrender in September 1945 ended active hostilities, but it did not immediately create a final peace settlement. Japan remained under Allied occupation, led by the Supreme Commander for the Allied Powers, while the terms of the postwar order were negotiated.

The peace treaty was signed at San Francisco on 8 September 1951. It came into force on 28 April 1952, ending the legal state of war and restoring Japan’s sovereignty. The treaty also addressed Japan’s renunciation of claims to territories acquired through its wartime expansion.

This distinction explains why the 1945 surrender and the 1952 treaty are both important. The surrender stopped the fighting and imposed the Allied terms; the treaty established the formal postwar peace. Japan and the Soviet Union followed a separate diplomatic path, signing the Soviet-Japanese Joint Declaration in 1956.