The Truman Doctrine
"We are willing to help free peoples maintain their institutions and their national integrity against aggressive movements that seek to impose upon them totalitarian regimes." --Harry S. Truman
At the end of 1945, after their victory over the Axis powers, the United States and the Soviet Union towered as the world’s dominant powers. But they divided along ideological lines, and so international politics assumed a zero sum nature: a gain in power by one country -- even if more potential than real -- automatically led to a corresponding loss in power to the other.
"The security of the United States was threatened," wrote John Spanier, "because any state, especially a state that was antidemocratic as well as undemocratic, that controlled all the resources – human, natural and industrial – of Eurasia, the Middle East and Africa, and that organized these resources and transformed them into military power, might some day be able to attack North America."
American President Harry Truman enunciated what came to be known as the "Truman Doctrine" in March of 1947. The precipitant was the meddling by outside forces in Greece. The policy he outlined, that of opposing Soviet gains wherever they occurred, became known as the doctrine of "Containment." With some modifications, Containment served as the basis for American foreign policy right up to the collapse of the Soviet Union in 1991.
Suspicion among nations is a feature endemic to any pluralistic regional system and, for that matter, the international system of states as a whole. Such suspicions can conceivably be eliminated under a single world government, assuming that the world’s people are willing to concentrate all power in a single center – and run the risk of enslaving themselves.