- George Kennan was the influential American diplomat who was the architect of the policy of containment, which was the basis of American foreign policy for over forty years. - The essential element of the policy of containment was a commitment to holding communism within the Soviet Union and Eastern Europe. - In 1947, President Truman told Congress that the United States would "support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures," which was first implemented in Greece and Turkey.