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.
United States–Vietnam relations
Although Washington's advisory role was essentially political, United States policy makers determined that the effort to erect a non-communist state in Vietnam was vital to the security of the region and would be buttressed by military means, if necessary, to inhibit any would-be aggressor. Defending Vietnam's security against aggression from the North and from southern-based communist insurgency was a mission Washington initially perceived as requiring only combat support elements and advisers to South Vietnamese military units. The situation, however, rapidly deteriorated, and in 1965, at a time when increasing numbers of North Vietnamese-trained soldiers were moving in South Vietnam, the first increment of United States combat forces was introduced into the South and sustained bombing of military targets in North Vietnam was undertaken. Nearly eight more years of conflict occurred before the intense involvement of the United States ended in 1973.