The Soviet invasion of Manchuria defeated Japan’s Kwantung Army.
The Kwantung Army was the Imperial Japanese Army formation responsible for defending Japan’s interests in Manchuria, where Japan had established the puppet state of Manchukuo. By 1945, many of its experienced units had been transferred to other fronts, leaving it less capable than its earlier reputation suggested.
Soviet forces launched the Manchurian Strategic Offensive Operation shortly after midnight on 9 August 1945. They attacked from the east, west, and north, using large mechanized formations and coordinated operations across difficult terrain.
The Kwantung Army officially surrendered on 16 August, although fighting in the region continued afterward. Its rapid defeat helped convince Japanese leaders that continued resistance could not preserve Japan’s position in Asia or produce better surrender terms.