More than a quarter of a century has now passed since Harry S. Truman proclaimed on March 12, 1947 that "it must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or outside pressures." At the time, government officials, Congressmen, journalists and other elements of the articulate public vigorously debated the merits of the Truman Doctrine, and in the intervening years historians have kept the argument going. Defenders have seen the statement as the moment when Americans abandoned isolationism once and for all, finally accepting, however reluctantly, their full responsibilities as a world power. Critics, conversely, have seen it as the beginning of the long process by which the United States became a world policeman, committing resources and manpower all over the world in a futile attempt to contain a mythical monolith, the international Communist conspiracy. But despite their differences, critics and defenders of the Truman Doctrine tend to agree on two points: that the President's statement marked a turning point of fundamental importance in the history of American foreign policy; and that U.S. involvement in the Vietnam War grew logically, even inevitably, out of a policy Truman thus initiated.
There can be no doubt that the President did employ sweeping rhetoric, implying an unprecedented commitment to resist communism wherever it appeared. But gaps between rhetoric and reality in U.S. foreign policy have often been large; indeed, such gaps might be said to constitute a defining characteristic of this country's diplomacy. Any reassessment of the Truman Doctrine, therefore, should consider first how far the statement in fact represented a radical departure from policies the United States was already following, and then to what extent the Truman administration sought to implement the wide-ranging program it so resoundingly proclaimed. I propose to argue that the Truman Doctrine, far from representing a revolution in American foreign policy, was very much in line with previously established precedents for dealing with shifts in the European balance