Soviet forces invaded Manchuria immediately before Japan’s 1945 surrender. The offensive began on August 9, 1945, against the Japanese-controlled state of Manchukuo in northeastern China.
The Soviet campaign involved forces attacking from the east, west, and north. Its main opponent was Japan’s Kwantung Army, which had once been one of the Imperial Japanese Army’s strongest formations but was weakened by transfers of troops to other fronts.
The invasion rapidly changed the strategic situation. Japan’s leaders had hoped that the Soviet Union might mediate a negotiated settlement, but the Soviet attack destroyed that diplomatic expectation. Soviet operations also extended into Korea, southern Sakhalin, and the Kuril Islands.
Manchuria is sometimes confused with the Japanese home islands because both areas appear in accounts of the surrender crisis. The Soviet offensive did not invade Japan’s main home islands before the surrender announcement, though Soviet leaders considered further operations, including a possible landing in Hokkaido.