Which 1945 Soviet military operation began against Japanese forces in Manchuria just before Japan surrendered?

The Soviet invasion of Manchuria began against Japanese forces just before Japan surrendered.

The Soviet Union declared war on Japan late on August 8, 1945, and launched its invasion of Japanese-occupied Manchuria shortly after midnight on August 9. Soviet forces attacked the Kwantung Army across several fronts, advancing through Manchuria and also striking Japanese positions in Korea, southern Sakhalin, and the Kuril Islands.

The operation was officially called the Manchurian Strategic Offensive Operation. It involved large Soviet formations, armor, artillery, and aircraft against Japanese forces that had been weakened by transfers to other fronts. The speed and scale of the offensive intensified the crisis facing Japan’s leaders.

The invasion was one of several decisive events surrounding Japan’s surrender, alongside the atomic bombings of Hiroshima and Nagasaki and the Allied warning in the Potsdam Declaration. It should not be confused with Operation Downfall, the planned Allied invasion of the Japanese home islands, which was never carried out.