On what date did the Treaty of San Francisco take effect, restoring Japan’s sovereignty?

The Treaty of San Francisco took effect on April 28, 1952, restoring Japan’s sovereignty after the Allied occupation.

The treaty, formally called the Treaty of Peace with Japan, was signed in San Francisco on September 8, 1951. It ended the legal state of war between Japan and most of the Allied powers and set out the terms for Japan’s return to the international community.

The agreement ended the Allied occupation and required Japan to renounce claims to several territories acquired during its imperial expansion. It was signed by 49 nations, although the Soviet Union did not become a party. China was not invited because the United States and other governments disagreed over whether the Republic of China or the People’s Republic of China represented China.

The treaty’s effective date is different from the surrender date in 1945. The 1945 instrument ended active hostilities, while the 1952 treaty formally concluded the postwar occupation and restored Japan’s sovereignty. A separate security treaty with the United States was signed on the same day in San Francisco.