Containment is a military strategy to stop the expansion of an enemy. It is best known as the Cold War policy of the United States and its allies to prevent the spread of communism abroad. A component of the Cold War, this policy was a response to a series of moves by the Soviet Union to enlarge communist influence in Eastern Europe, China, Korea, Africa, and Vietnam. Containment represented a middle-ground position between detente and rollback, but it let the opponent choose the place and time of any confrontation.The basis of the doctrine was articulated in a 1946 cable by U.S. diplomat George F. Kennan during the post-WWII administration of U.S. President Harry Truman. As a description of U.S. foreign policy, the word originated in a report Kennan submitted to U.S. Defense Secretary James Forrestal in 1947, a report that was later used in a magazine article. It is a translation of the French cordon sanitaire, used to describe Western policy toward the Soviet Union in the 1920s.