The Munich analogy was increasingly used by Washington to justify various actions during the Vietnam War. In 1954, when the French were nearing defeat in Vietnam, Eisenhower considered sending additional aid to supplement the economic aid already being supplied. In fact, by this stage, the United States was already funding three-quarters of the cost of the war but had not actually intervened militarily. Eisenhower considered this move and sought British support to use U.S. air and naval power in Indochina. In a letter to Winston Churchill, he used the Munich analogy in order to persuade the British to support American actions: "If I may refer again to history; we failed to halt Hirohito, Mussolini and Hitler by not acting in unity and in time. That marked the beginning of many years of stark tragedy and desperate peril. May it not be that our nations have learned something from that lesson?"
That John F. Kennedy thought and acted upon the same assumptions can hardly be open to question. In his words:
Viet-Nam represents the cornerstone of the Free World in Southeast Asia, the Keystone of the arch, the finger in the dike. Burma, Thailand, India, Japan, the Philippines and obviously Laos and Cambodia are among those whose security would be threatened if the red tide of Communism overflowed into Viet-Nam…. Moreover, the independence of Free Viet-Nam is crucial to the free world in fields other than military. Her economy is essential to the economy of all of Southeast Asia; and her political liberty is an inspiration to those seeking to obtain or maintain their liberty in all parts of Asia—and indeed the world.
For these reasons, added Kennedy, "the fundamental tenets of this nation's foreign policy …depend in considerable measure upon a strong and free Vietnamese nation."
Under Kennedy, the number of U.S. troops in South Vietnam increased steadily, reaching some 14,500 before the end of 1963. Technically, they were engaged only in transportation, training, and advice, but these activities invariably exposed them to combat. Few questioned why they were there.
It was not until the advent of the Johnson administration, however, that the Munich analogy came into its own. President Lyndon B. Johnson and his secretary of state, Dean Rusk, considered Munich to be the most important historical lesson of their time. Remembering Munich, they saw weakness overseas as leading to World War III. Johnson explained, "Everything I knew about history told me that if I got out of Vietnam and let Ho Chi Minh run through the streets of Saigon, then I'd be doing exactly what Chamberlain did in World War II. I'd be giving a big fat reward to aggression." Rusk was equally attuned to the lessons of the 1930s, which he described as the realization that "aggression must be dealt with wherever it occurs and no matter what mask it may wear…. The rearmament of the Rhineland was regarded as regrettable but not worth a shooting war. Yet after that came Austria, and after Austria came Czechoslovakia. Then Poland. Then the Second World War."
This belief in the applicability of the Munich analogy to his situation led Johnson to increase troop levels, first to 300,000 and then to 500,000 by 1968. At a National Security Council meeting in July 1965 to discuss an increase in troops, an exchange occurred between Undersecretary of State George Ball, who was opposed to committing more men, and the U.S. ambassador to Vietnam, Henry Cabot Lodge. Lodge rebutted Ball's arguments, explaining that "I feel there is a greater threat to start World War III if we don't go in. Can't we see the similarity to our own indolence at Munich?" No one present at the meeting questioned this statement. Even McGeorge Bundy, the national security adviser who often criticized others for using inaccurate analogies, did not comment. The administration's policymakers were convinced of the appropriateness of the analogy to their own situation in Vietnam, and often reminded one another of this fact. Even former president Eisenhower resorted to the analogy in advising Johnson in 1965. He warned the president not to be convinced by Britain's arguments for negotiation. Prime Minister Harold Wilson, he said, "has not had experience with this kind of problem. We, however, have learned that Munichs win nothing."
Most important, the Johnson administration used the analogy to convince the public that its Southeast Asia policy was appropriate. A government film produced in 1965 entitled Why Vietnam? contained flickering images of Neville Chamberlain at Munich throughout the film. Further, when announcing his decision to send combat troops to Vietnam in March 1965, Johnson explained to the public: "Nor would surrender in Vietnam bring peace, because we learned from Hitler at Munich that success only feeds the appetite of aggression. The battle would be renewed …bringing with it perhaps even larger and crueler conflict, as we learned from the lessons of history."
In the same year, Johnson argued that defeat in South Vietnam "would encourage those who seek to conquer all free nations within their reach…. This is the dearest lesson of our time. From Munich until today we have learned that to yield to aggression brings only greater threats." Worse yet, a new wave of McCarthyism might pose rhetorical questions about how Vietnam was lost.
Similarly, Richard M. Nixon's policy of détente with the Soviet Union and China failed appreciably to alter the image of Vietnam as a vital test case and an aspect of a larger problem. "An American defeat in Viet-Nam," declared Nixon on 8 May 1972, in a message to the American people explaining his decision to mine the entrances to North Vietnamese ports, "would encourage this kind of aggression all over the world…. Small nations, armed by their major allies, could be tempted to attack neighboring nations at will, in the Mid-East, in Europe and other areas."
No change was to be expected in the attitude of Gerald Ford's administration. In his formal and foredoomed request to Congress in early 1975 for continued military aid to South Vietnam (and Cambodia), President Ford reminded his recent colleagues that "U.S. unwillingness to provide adequate assistance to allies fighting for their lives would seriously affect our credibility as an ally." Saigon fell on 30 April. The collapse of South Vietnam together with the defeat of the pro-Western forces in Cambodia and subsequently in Laos marked the end of American influence in the area. For some, it came as no real surprise, for others, there were no words to explain it. The Munich analogy, in time, gave way to the "Vietnam syndrome," which led many Americans to question the wisdom of using military power at all.