At the height of the Second Indochina War, Washington officials typically explained U.S. involvement in international terms. The demands of American “credibility” necessitated standing firm in Vietnam, they said, even if that meant committing U.S. ground troops to fight and die there. U.S. prestige was on the line in Southeast Asia as a result of many years of steadily expanding involvement in the struggle and constant public assertions of South Vietnam's importance to American security. An early withdrawal from the war, so the argument went, would cause allies elsewhere in Asia and around the world to lose faith in the reliability of America's commitments and would embolden adversaries in Moscow and Beijing to pursue aggressive designs all over the globe.

In fact, however, neither friends nor foes around the world tended to see American credibility as being at stake in Vietnam. The newly opened archives in Western Europe and Canada, as well as those in the United States, show that key allied governments believed at the end of 1964 that U.S. credibility would suffer more from a deepened commitment to what they saw as an incompetent and corrupt (and increasingly anti-American) Saigon government than from some kind of fig-leaf withdrawal. What these powers questioned was not America's will but its judgment. Canada, France, Great Britain, Japan - all these nations registered private opposition to Americanization in the key months of mid-1964 to 1965.