President Truman tried to check the spread of socialist and communist movements by giving aid to anti-socialist regimes. The policy became known as the Truman Doctrine, as the President outlined these intentions with his request for monetary aid for Greece and Turkey. Both countries were about to be taken over by Soviet-backed guerrilla movements. Truman decided to act and in 1947, he asked Congress for $400 million to send to these two nations in the form of military and economic assistance. Within two years the communist threat had passed, and both nations were comfortably in the western sphere of influence.
The U.S.A started to influence the affairs of Europe more than ever before. In the time, when Europe was suffering after the war, the United States came with the Marshall Plan. It was an offer to all European countries needing help in their recovery and reconstruction introduced in 1947. The plan was announced by George Marshall, the Secretary of State. To avoid antagonizing the Soviet Union, Marshall announced that the purpose of sending aid to Western Europe was humanitarian, and even offered aid to the communist states in the east. Congress approved the request of $12 billion over four years to be sent to Europe. Alltogether, eighteen countries joined the American scheme and the plan became the basis of their economies. Countries, which were under the Soviet influence, refused the help.
The world trying to recover from one war almost immediately began another, the Cold War of economic as well as diplomatic struggles. Winston Churchill's 1946 speech to Westminster University in Missouri contained the first reference to the communism of Eastern Europe as an iron curtain which had descended across the continent. In 1949, the West European countries together with the United States and Canada formed a military organization called the North Atlantic Treaty Organization (NATO) as a system of collective defence.