Why did the United States develop the containment policy, and how did the Truman administration implement it?
The policy of containment was developed by the United States as a response to the way in which communism seems to be spreading unchecked abroad. This policy was therefore part of the Cold War and a response to moves by the USSR to enlarge communist influence, particularly in Eastern Europe and Asia. This policy is most strongly associated with the term of President Truman, and ways in which he sought to realise this policy included the establishment of the North Atlantic Treaty Organisation (NATO), which was essentially a mutual defence pact, and featured the creation of a rival block of power that at least stood in opposition to the powermongering of the Soviet Union. The policy of containment is not exclusively associated with Truman, however, and other presidents used it as part of their foreign policy in the Cold War, most notably Johnson, who cited containment as justifying his intervention in Vietnam.