What policy aimed to contain the spread of communism during the Cold War?

The policy that specifically aimed to contain the spread of communism during the Cold War is the Truman Doctrine. Introduced in 1947, this doctrine was a response to perceived threats of communism in Greece and Turkey, where the United States sought to provide political, military, and economic assistance to countries resisting Soviet influence and communist insurgencies. The Truman Doctrine established containment as a core strategy of U.S. foreign policy, emphasizing that the U.S. would support free peoples who were resisting attempted subjugation by armed minorities or outside pressures.

While the Domino Theory relates to the belief that the fall of one nation to communism would lead to the fall of neighboring nations, it was more of a justification for intervention rather than a direct policy like the Truman Doctrine. The Marshall Plan focused on economic recovery in Europe post-World War II, and the Eisenhower Doctrine was aimed more specifically at the Middle East. The Truman Doctrine is, therefore, the foundational policy that defines America's approach to containing communism during the early years of the Cold War.