The warfare that occurred after the supposed peace of 1973 developed in three stages.
From early to mid 1973, the Saigon government was on the offensive. The Communists, busy rebuilding their supplies and their supply lines, and wanting to avoid provoking the US into resuming combat operations in Vietnam, stayed mostly on the defensive.
In late 1973 and most of 1974, with the Nixon administration collapsing and their own forces growing stronger, the Communists were about as aggressive as the Saigon government.
In January 1975, the Communists (mainly North Vietnamese forces) finally resumed serious efforts to destroy the Saigon government. Communist commanders apparently expected that the job would take a year or two, but when the North Vietnamese offensive began, significant portions of the ARVN disintegrated in panic. ARVN units abandoned some important towns without even waiting to be attacked; some ARVN officers abandoned their men. This should not be exaggerated; considerable parts of the government forces continued to fight, with skill and determination. But enough units broke to render a coherent, organized defense impossible. Communist commanders realized that they could conquer all of South Vietnam in a very short time if they just kept the momentum of their offensive going. Communist forces, mostly North Vietnamese but including some PRG personnel, marched into Saigon at the end of April, 1975.
The United States had cut back military aid to the ARVN in the last years of the war. The US Congress was not willing to put big money into Vietnam, once there were no longer US troops on the ground there, needing the support. The Congress only appropriated $700,000,000 in military aid to South Vietnam for the fiscal year that ran from July 1974 through June 1975; the war ended with the collapse of South Vietnam shortly before the end of this fiscal year. There was also some economic and humanitarian aid. There is a widely believed myth that the US Congress cut off US aid to South Vietnam near the end of the war, but this is not true. Deliveries of US military aid were still arriving in Saigon 48 hours before the North Vietnamese troops rolled into the city.
Vietnam War Bibliography lists works on all aspects of the war, some of them available online.
Copyright © 1998, 2004, 2014, Edwin E. Moise. Opinions expressed in this page are my own. They could not very well be the opinions of Clemson University, which does not have opinions on the subjects involved. Revised July 20, 2014.