How effectively did the United States meet the challenge of Communism during the years 1945-1954?

How effectively did the United States meet the challenge of Communism during the years 1945-1954?

Be sure to define your terms as necessary. At the very least, you will have to explain what challenge communism posed, what an effective response was (or would have been) given the situation at the time, and whether the United States attained that.