Why wasn't the war against Ho Chi Minh noble?

Because North Vietnam was communist. Anything anti-communist was bad here in Sixties America.

I haven't heard Prager use the term "anti anti-communist" in a couple of years. It's a very useful term, he should start using it again.

But as I started to say, anything anti-communist was bad here in Sixties America; the hippies redefined our language and took over the goods and bads and evils in our culture, so that eventually even a simple phrase was sufficient to eviscerate the argument, the position, the arguer, all in one two-word phrase. "You're so middle class" would shoot down everything the person had said, was then saying, and ever would say in the entire remainder of his existence. "Don't be so judgemental" would shut them up forever, at least in the presence of the judging anti-judger, who forever owned all arguments and all righteousness.

The judges of righteousness also dismissed capitalism forever as "evil" and "selfish". Discrimination, including discriminating against evil, was bad, though it was certainly okay to discriminate against conservatives and Republicans and against white men (and soon after, against white boys).

They used the same rhetoric to eliminate majority positions all across Western civilization. It became embarrassing to believe in God (Flying Spaghetti Monster or sky fairies) though it was okay to believe in Buddha, Vishnu, Khali, engrams, Allah, chakras, your horoscope, and all sorts of other stupidities. Patriotism was mocked, making money became filthy, opposing high taxes was "racism" (if you don't remember that, you shouldn't vote)--because they assumed in a most racist manner that the beneficiaries of the redistribution of wealth were all black.