On what date did the Treaty of San Francisco legally end the state of war with Japan?

The Treaty of San Francisco legally ended the state of war with Japan when it came into force on April 28, 1952.

Japan’s military surrender in September 1945 ended the fighting, but a separate peace treaty was needed to restore Japan’s full sovereignty and establish postwar legal relations. The treaty was signed in San Francisco on September 8, 1951, by Japan and 48 Allied countries.

The agreement ended the Allied occupation and formally restored peaceful relations with the participating Allies. It also required Japan to accept the judgments of Allied war-crimes tribunals and renounce claims to territories acquired through its imperial expansion.

This date is different from both V-J Day and the surrender ceremony. September 2, 1945 marked the formal military surrender, while April 28, 1952 marked the treaty’s entry into force. The Soviet Union did not sign the treaty; Japan and the Soviet Union later ended their state of war through a 1956 joint declaration.