Which Japanese military force was defeated during the Soviet invasion of Manchuria in 1945?

The Kwantung Army was the Japanese military force defeated during the Soviet invasion of Manchuria in 1945. It was responsible for defending Japanese interests in Manchukuo and had played a central role in Japan’s seizure and control of Manchuria.

The Red Army launched its offensive on August 9, attacking from multiple directions with large armored and mechanized forces. The campaign exposed the Kwantung Army’s weakened condition. Many experienced Japanese units had been transferred to other fronts, leaving the formation less capable of resisting the Soviet advance than its reputation suggested.

The defeat destroyed Japan’s strategic position in northeastern Asia. Japanese leaders had hoped the Soviet Union might mediate between Japan and the Western Allies, but the Soviet attack eliminated that possibility. Soviet forces also moved into northern Korea, southern Sakhalin, and the Kuril Islands.

The Kwantung Army continued fighting in some areas after Japan’s surrender announcement, but its organized resistance collapsed rapidly. Its defeat is regarded as one of the major military developments surrounding Japan’s decision to accept the Allied surrender terms.