Answer:
Truman Doctrine
The Truman Doctrine was first stated by the president to Congress in 1947, saying: "It must be the policy of the United States to support free people who are resisting attempted subjugation by armed minorities or by outside pressures." Essentially, the Truman Doctrine pledged American effort elsewhere in the world to check the spread of communist and Soviet influence. The policy was first put into action in 1948 by providing economic support to Greece and Turkey to stave off communist movement in those countries. The essence of this policy was called "containment" -- keeping communism where it was and stopping it from spreading.
