There were eight ways in which the United states of America attempted to control communism: by agreement, by the deterrent of nuclear weapons, by applying the Truman doctrine, by economic measures under the marshal plan, by propaganda, by non-cooperation with the USSR, by form action and by military alliance.
The first method the USA applied to contain communism was agreement. This can be seen as attempt at the Yalta and Potsdam conferences of 1945. this method was as history proves not very effective because it did not contain communism and the measures agreed upon were not respected, i.e. free election in eastern Europe.
The method of military deterrent was not very effective either. It aimed to contain communism through the US's military superiority. This was not effective because the technology was not superior enough not be attained by the USSR. The USSR getting the atomic bomb in 1949 and the h bomb in 1953.
Thus the measure of 'scaring' the USSR and thus containing communism was not effective.
The Truman doctrine of 1947 was created to 'save' Greece from communism. The saving was to be done through helping Britain with military and financial aid to fight communism in Greece. But the policy was extended to aid any country under the threat of communism. The Truman doctrine was effective considering that much of the eastern block had already fallen to communism by the time it was implemented. Furthermore it did prevent Greece form falling to communism.