Operation Unthinkable: Churchill's Secret Plan to Attack the Soviet Union

World History: True Stories of the 20th Century · Jun 10, 2026 · 14m

Operation Unthinkable was a secret British military plan developed in 1945 that explored the possibility of war between the Western Allies and the Soviet Union immediately after the defeat of Nazi Germany. Conceived under the direction of British Prime Minister Winston Churchill, the plan reflected growing concerns about Soviet expansion in Eastern Europe and the future balance of power on the continent.

As World War II drew to a close, the alliance between Britain, the United States, and the Soviet Union began to fracture. Churchill had long distrusted Joseph Stalin and viewed Soviet…