History of the United States (1964–1980)
The growing Watergate scandal was a major disaster for Nixon, eroding his political support in public opinion and in Washington. However he did manage to secure large-scale funding for South Vietnam, much of which was wasted. The United States withdrew its troops from Vietnam before the Paris Peace Accords in 1973. However, Watergate resulted in significant Democrat gains in the 1974 midterm elections and when the new 94th Congress convened the following January, it immediately voted to terminate all aid to South Vietnam in addition to passing a bill forbidding all further US military intervention in Southeast Asia. President Ford was against this, but as Congress had a veto-proof majority, he was forced to accept. South Vietnam rapidly collapsed as the North invaded it in force, and Saigon fell to the NVA on April 30, 1975. Later nearly one million Vietnamese managed to flee to the U.S. as refugees. The impact on the U.S. was muted, with few political recriminations, but it did leave a "Vietnam Syndrome" that cautioned against further military interventions anywhere else. Nixon (and his next two successors Ford and Carter) had dropped the containment policy and were not willing to intervene anywhere.
Howard Zinn
Zinn wrote one of the earliest books calling for the U.S. withdrawal from its war in Vietnam. "Vietnam: The Logic of Withdrawal" was published by Beacon Press in 1967 based on his articles in "Commonweal", "The Nation," and "Ramparts". In the opinion of Noam Chomsky, "The Logic of Withdrawal" was Zinn's most important book:"He was the first person to say—loudly, publicly, very persuasively—that this simply has to stop; we should get out, period, no conditions; we have no right to be there; it's an act of aggression; pull out. It was so surprising at the time that there wasn't even a review of the book. In fact, he asked me if I would review it in "Ramparts" just so that people would know about the book."