The Soviet–Japanese War (Russian: Советско-японская война; Japanese: ソ連対日参戦, romanized: soren tai nichi sansen, lit. 'Soviet Union entry into war against Japan'), known in Mongolia as the Liberation War of 1945 (Mongolian: 1945 оны чөлөөлөх дайн, romanized: 1945 ony chölöölökh dain) was a military conflict within the Second World War beginning soon after midnight on 9 August 1945, with the Soviet invasion of the Japanese puppet state of Manchukuo. The Soviets and Mongolians ended Japanese control of Manchukuo, Mengjiang (Inner Mongolia), northern Korea, Karafuto (South Sakhalin), and the Chishima Islands (Kuril Islands). The defeat of Japan's Kwantung Army helped bring about the Japanese surrender and the termination of World War II. The Soviet entry into the war was a significant factor in the Japanese government's decision to surrender unconditionally, as it was made apparent that the Soviet Union was not willing to act as a third party in negotiating an end to hostilities on conditional terms.