The most interesting thing I learned when we visited Vietnam was the big duh moment for me when I realized the Vietnamese people didn't call it the Vietnam war. They called it the American War. Because - it was an American invasion. So interesting. We went to the Ho Chi Minh museum and learned about all of the various invasions over the centuries. The Vietnamese were skilled at being an occupied population and they never ever gave up.
They even expelled the Mongols for heaven's sake. How did the Americans imagine they could succeed?