The Presidential terms of Harry S Truman and Richard M. Nixon straddle respectively the beginning and the end of the most active phase of the Cold War, the era of active, large scale U.S. military intervention against Communist advances in Third World countries. This period of U.S. anticommunist interventionism lasted almost exactly twenty five years. It began in July of 1950, with the North Korean invasion of South Korea, to which the U.S. quickly responded in force, beginning the Korean War. It ended in April, 1975, when a North Vietnamese invasion of South Vietnam culminated with a panicky escape by helicopter from the roof of the American embassy in Saigon.
Nixon himself was no longer in office by that time. He had been forced to resign in disgrace over the Watergate scandal the previous August, but the fall of Saigon marked the final failure of Nixon's policy of "peace with honor" in Vietnam, and more broadly the end of the era of active intervention which had begun under Truman in 1950, and which culminated in two major land wars, neither of which the U.S. could really say it won, and one of which, by almost any standard, it clearly lost.
The experiences of Korea and Vietnam have continued to haunt American culture and policy. Korea has been called the "forgotten war." A generation of Americans know it best through the movie and television show M*A*S*H which, though nominally about Korea, was a post Vietnam era show that was "really" about Vietnam. Today the two seem to be grouped together, as if Vietnam was the natural culmination of Vietnam. Their twin shadow still looms. Carter era "retreatism" was a reaction to Vietnam. Reagan era bluster was a reaction to the reaction but U.S. policymakers, even under Reagan, and still today under Bush, are terrified by "quagmires" and the specter of another "no win war."
Vietnam, then, represented the failed end of a policy tradition which be...