Which 1951 peace treaty formally ended the state of war between Japan and most Allied powers?

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

Japan signed the treaty on 8 September 1951, and it entered into force on 28 April 1952. The agreement restored Japan’s sovereignty after the Allied occupation and established the postwar legal framework between Japan and the participating Allied countries.

The treaty followed the 1945 surrender but was not the same event. The Japanese Instrument of Surrender ended active hostilities and established the surrender arrangements. The San Francisco treaty came later as a peace settlement, addressing sovereignty, territory, reparations, and Japan’s international status.

The treaty did not settle every diplomatic relationship. The Soviet Union did not sign it, and Japan’s state of war with the Soviet Union formally ended through the Soviet–Japanese Joint Declaration of 1956. Japan also signed the separate Treaty of Taipei with the Republic of China in 1952.