Manchuria was the first major Japanese-held region attacked by the Soviet Union in August 1945. Soviet forces began the invasion of Japanese-occupied Manchuria on 9 August 1945 in the final weeks of World War II.
The campaign targeted Manchukuo, Japan’s puppet state in northeastern China, and involved a massive Soviet offensive against the Kwantung Army. Soviet forces attacked from several directions, using armor, artillery, aircraft, and coordinated advances across difficult terrain.
The invasion was a major factor in the rapid collapse of Japan’s strategic position. Japan had hoped that the Soviet Union might mediate with the Western Allies, but Moscow instead declared war and attacked. The offensive began between the atomic bombings of Hiroshima and Nagasaki.
Manchuria should not be confused with Okinawa, where U.S. forces fought a major campaign earlier in 1945, or Korea, where Soviet troops also advanced during the final offensive. The principal opening target of the Soviet operation was Japanese-occupied Manchuria.