Which 1945 Soviet campaign against Japan began in Manchuria shortly before Japan surrendered?

The Soviet invasion of Manchuria was the 1945 campaign against Japan that began shortly before Japan surrendered.

The Soviet Union declared war on Japan on 8 August 1945, and Red Army forces began their attack across Manchuria in the early hours of 9 August. The offensive targeted Japanese forces and the Japanese-controlled puppet state of Manchukuo.

The campaign advanced from several directions and rapidly overwhelmed the Kwantung Army, which had once been one of Japan’s most powerful formations. Soviet forces also moved into areas including Inner Mongolia, northern Korea, southern Sakhalin, and the Kuril Islands.

The invasion complicated Japan’s hope that Moscow might mediate a negotiated peace. Historians continue to debate the relative importance of the Soviet offensive and the atomic bombings, but both developments sharply influenced Japan’s final decision to accept the Allied terms.