Greece
Greece was in a state of chaos because of the war, and a Civil War broke out, lasting between 1944 and 1949. The Greek government, backed openly by the USA and Britain, fought the Greek communists, who had their own army, which had been formed during the earlier years of the war and had helped to liberate Greece from the Nazis.
Turkey
In 1945,The Soviet Union demanded that Turkey let it set up naval bases in its own backyard.
Truman Doctrine
Events in Turkey and Greece made Harry S Truman decide he’d had enough of Soviet meddling, and he adopted the Truman Doctrine. In addition to pledging military and economic aid to Greece and Turkey, it also declared that the USA had the duty to “support free people who are resisting attempted subjugation by armed minorities or by outside pressures.” And when Truman said ‘outside pressures’, he basically meant ‘communists’.
The Truman Doctrine was an important next step in creating the Cold War, in that the USA was now formally committed to taking on communist movement anywhere and everywhere, while the Soviet Union was firmly committed to supporting them.
Marshall Plan
Another US weapon against a Soviet-backed rise of communism across the world was the Marshall Plan, announced in June 1945 which basically gave European countries affected by the war the offer of lots and lots of money to help them to rebuild. Stalin interpreted this as the USA trying to buy the loyalty of European countries, and banned the Eastern European communist countries (whose communist parties by 1947 were joined in a group called the Cominform) from accepting this aid.