Why was the Vietnam War (1965-73) such a devastating loss to the American national-collective psyche whereby America — both as a society and in our military — suffered from what could be called a national “Vietnam syndrome” since the Fall of Saigon in 1975?

Why was the Vietnam War (1965-73) such a devastating loss to the American national-collective psyche whereby America — both as a society and in our military — suffered from what could be called a national “Vietnam syndrome” since the Fall of Saigon in 1975?  In what ways has the U.S. recovered or not, since its victory in the 1990-91 Persian Gulf War and through its military interventions overseas after 9-11?