The NVA was a disciplined regular army with thousands of tanks (I read General Giap's book, darn it). Many ARVN units fought bravely to the end. But the ANA folded like a cheap suit against a guerrilla force it drastically outgunned and outnumbered. And worse, our own military, intelligence, and diplomatic bureaucracy didn't realize how bad things were.
It might help if you defined your acronyms.
They did but weren’t allowed by higher ups to say it.