What 1956 declaration formally ended the state of war between Japan and the Soviet Union?

The Soviet-Japanese Joint Declaration of 1956 formally ended the state of war between Japan and the Soviet Union.

Japan and the Soviet Union signed the declaration in Moscow on 19 October 1956, and it took effect on 12 December of that year. The document restored diplomatic relations and declared that the two countries’ state of war had ended.

The agreement did not settle every issue left by World War II. In particular, the territorial dispute over several Kuril Islands continued. The Soviet Union agreed to transfer Shikotan and the Habomai Islands after a peace treaty, but no comprehensive peace treaty followed.

This declaration is separate from the Treaty of San Francisco, which Japan signed with many Allied powers in 1951. Because the Soviet Union did not sign that treaty, Japan and the USSR needed their own diplomatic settlement after the 1945 surrender.