As one soldier pointed out in one of the episodes, the military always starts out fighting a war in the exact same way they fought the last war. They usually discover that warfare has changed, and the question becomes how quickly can your army adapt.
A North Vietnamese soldier explained the plans of their commanders quite nicely. He said their commanders told them "we have to fight them by grabbing their belt buckles. We grab their belt buckles, we win. We don't grab their belt buckles, we will be killed by their mortar fire and their planes."
Burns has done a really nice job thus far laying out the deadly cocktail that was Vietnam. A fear of encroaching Communism without asking the question, "Who farking cares if the communists take over Vietnam? It's Vietnam for crying out loud." The American Exceptionalism that expanded into arrogance through the years following WWII. An unconventional battlefield that didn't permit you to measure wins and losses by ground gained or cities captured, but required creation of a new measuring tool (body count) that only encouraged lying to save face, and once you start lying about that, where does the lying stop?
It will be interesting to see if this documentary changes American opinion about its Vietnam vets. Getting a little late now, but I suppose better late than never.