And why, pray tell, was that??? Could it have possibly been the 'Rat Congress of 1974, which started the grand 'Rat tradition of backstabbing of American allies for politically expedient reasons?
The Vietnam War was essentially won when the Paris peace accords were signed: the South Vietnamese were promised continued military assistance following the withdrawal of US troops. Thanks to the 'Rats, that lifeline was pulled and in less than 2 years, the Communists marched into Saigon while American helicopters evacuated the US Embassy.
And the tradition continues to this day with the lack of a status-of-forces agreement before the Iraq withdrawal and a timetable for Afghanistan withdrawal that Taliban forces have penciled in on their calendars.
FUBO and FAD!
Then the Khmer Rouge seized power in Cambodia, and left 2 million dead. Ironically it took the Communist Vietnamese to put a stop to it.
To be fair, Nixon started the downhill roll. LBJ left him a mess, but the commies handed us the massive victory of Tet. Had Nixon been able to capitalize on that victory in 1968 General Creighton Abrams would have won the war. He was very supportive of what the Marines were doing in their sector.
Abrams was going to win and his strategy was sound. Even if Vietnamization had gone forward as quickly, the war wasn’t lost. If the AVRN had had US air and artillery support for their ground operations they would have whomped the NVA going forward. They were increasingly more effective and once their incompetent general was fired they would have just gotten better.
That doesn’t excuse Frank Church who essentially handed victory to the commies.