Read McMaster's Book...."Dereliction of Duty"....if you want a better understanding of how the United States Military and Civilian Leadership set out to lose the War....and succeeded handsomely.
The real key change in the way the War was fought is when Westmoreland got the can tied to his tail (incompetence promoted upwards....) and Creighton Abrams took over.
The Book about Abrams...."Thunderbolt" is very informative.
Forty plus years later I have a much different understanding of the War than I did during my two Tours there flying Chinooks.
I also have lots of questions about for the Management that I would very much like answered.