Containment was the central message of the Truman Doctrine. The United States pledged to support free peoples who were resisting subjugation by armed minorities or outside pressures, in accordance with the principles set forth in the United Nations Charter. This policy was put into practice in Greece and Turkey, where the US provided military and economic assistance to help those countries resist communist insurgencies. The Truman Doctrine marked the beginning of the Cold War, a global conflict between the US and the Soviet Union that lasted for over four decades.