During the Soviet–Japanese War in August 1945, the Soviet Union made plans to invade Hokkaido, the northernmost of Japan's four main home islands.

[2][3] Although all other Allies, including the United States, ceased all hostilities upon the surrender, Stalin ordered his troops to continue fighting to capture more Japanese territory[4]: 28  and to put the Soviets in a stronger bargaining position to occupy Japan.

[5] However, the previous month's Potsdam Declaration set out that postwar Japan would control its four main home islands of Hokkaido, Honshu, Kyushu, and Shikoku.

[11][9] Furthermore, concerns were raised within the Soviet high command that an invasion of Hokkaido would be impractical, be unlikely to succeed, and violate the Yalta Agreement.

[1]: 155–156 [5] The invasion was cancelled on 22 August, two days before their scheduled start, and Soviet forces concentrated on taking the Kuril Islands instead.