On 15 June, I gave my presentation on the fall of Saigon to Post 156 of the American Legion of which I am a proud member. As I finished speaking and was taking questions, one member asked why the Army of the Republic of Vietnam (ARVN, the South Vietnamese army) fought so poorly and lost the war after the U.S. withdrawal. My answer was that I observed some below-par ARVN units, but most fought valiantly. I cited the heroic battle for Xuan Loc which the North Vietnamese turned into a meat grinder, throwing more and more forces again the ARVN 18th Infantry Division until the communists finally prevailed on 21 April 1975, just eight days before the fall of Saigon. I said that Vietnam fell not because of the failure of ARVN but because the U.S. withdrew its military and financial support. My questioner rejected my answer.
I just started reading Losing Vietnam, a 2013 book by U.S. Army Major General Ira A. Hunt, Jr (retired). I’ll note here what I think of the book after I complete it, but it starts citing the U.S. unkept promises after the signing of the Peace Accords in 1973. We had pledged to provide air support for the ARVN and maintain the flow of money to keep the Republic of Vietnam (South Vietnam) afloat. But the unpopularity of the war led the U.S. Congress to terminate all air operations in August 1973. In July 1974, it drastically reduced funding for South Vietnam. In April 1975, it refused to increase the funding. Saigon fell at the end of the month.
In effect, the Congress’s action crippled ARVN. It couldn’t pay its soldiers or buy ammunition or replace lost weapons and equipment.
In sum, Vietnam fell to the communists because the U.S. population turned against the war and demanded that the Congress withdraw funds.
We have handled the wars in Iraq and Afghanistan in a similar fashion. And in all three conflicts, when the war became unpopular, we withdrew our forces and aid and abandoned the people who had fought at our side to the mercies of the enemy. In Vietnam, scores of thousands of South Vietnamese who had worked and fought at our side were killed or imprisoned and tortured by the North Vietnamese. Two thousand seven hundred ARVN who worked with my organization were abandoned to their fate. Surely we can do better than that in the future.