U.S. President Harry Truman provided post-war aid to the non-Communist side in Greek politics who, with that help, carried the day. The Greek Communists didn't go away, their heirs still battle for control of Greece.
Go see this Wall Street Journal article which talks about Greece slowly sinking into anarchy and possible civil war. I am concerned our current President, unlike Democratic President Truman, won't see the need to continue the Cold War fight against Communism.