Who said that communism could not be allowed to spread from the cold war?

During the Cold War, U.S. President Harry S. Truman articulated the belief that communism should not be allowed to spread, which became a cornerstone of U.S. foreign policy. This policy was further defined in the Truman Doctrine, announced in 1947, which aimed to contain communism and support free peoples resisting subjugation. The phrase "containment" became synonymous with this approach, emphasizing the need to prevent the expansion of Soviet influence globally.