April 28, 1952

Treaty of San Francisco

Peace Treaty with Japan Takes Effect and SCAP Occupation Ends

Japan's occupation formally ended not in Tokyo but in Washington, when an American ratification document was deposited at 9:30 in the morning.

9:30 a.m. at the State Department

On 28 April 1952, at a ceremony in the U.S. Department of State, the United States deposited its instrument of ratification of the Treaty of Peace with Japan. That satisfied Article 23(a) and brought the treaty into force at 9:30 a.m. Eastern Standard Time.

The office and organization of the Supreme Commander for the Allied Powers ended, and the U.S. Embassy in Japan was reestablished.

Immediately afterwards the two governments exchanged ratifications of their bilateral Security Treaty, bringing that agreement into force as well.

Nine parties, not forty-nine

The treaty had been signed in San Francisco on 8 September 1951 by 49 states including Japan. It initially took effect between Japan and nine of them: Argentina, Australia, Canada, France, Mexico, New Zealand, Pakistan, the United Kingdom and the United States.

It therefore ended the state of war only where it had entered into force. The Soviet Union had attended the 1951 conference but did not sign, so the Soviet-Japanese state of war was untouched.

Within moments of the treaty taking effect, Ryuji Takeuchi — previously head of the Japanese Government Overseas Agency in Washington — presented credentials as Japan's chargé d'affaires to Secretary of State Dean Acheson.

Sovereignty with two asterisks

"Full sovereignty" needs qualification. Article 3 continued U.S. administration of the Ryukyu and other specified islands, and the simultaneously effective Security Treaty authorized continued U.S. forces in and around Japan.

The end of SCAP did not mean every U.S. soldier or administration left every Japanese-claimed island that day.

Nor was 28 April a signing date, or a Japanese ceremony: the legal trigger was the American deposit of ratification in Washington.

Sources

Researched 24 Aug 2026 5 sources not yet audited

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What the sources leave uncertain

The treaty ended the state of war only between Japan and countries for which it entered into force; it did not create peace simultaneously with every wartime Allied state.
“Full sovereignty” needs qualification: Article 3 continued U.S. administration of the Ryukyu and other specified islands, while a separate security agreement authorized continued U.S. forces in and around Japan.