Two of the best books I read on this war are A Bright Shining Lie: John Paul Vann and America in Vietnam, https://images-eu.ssl-images-amazon.com/images/I/51sbxvnM26L._AC_US327_QL65_.jpg
and Chickenhawk
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Both superb books, the first in particular shows how the lies were sold to the American public as the war ground on.
I was in Subic Bay O club drinking with an American Admiral and an Air force Colonel in '71 towards the end when no-one back home supported the war, yet the Services were still expected to prosecute it to the fullest of their ability. These guys were practically crying in their beer!
Indeed. Two of my male American friends were retired US military, one a Lietenant Colonel instructing on B52's and the other flying Hueys helicopters during the Nam conflict. The latter would never enter into a conversation about the war; the former said he always flew above it, but again said little.
When I was at university I studied the Vietnam War and, in addition to what I already knew about it having been a teenager during the war's latter years, I read exactly why few Americans want to know anything about it! I studied in particular the possibility that JFK was about to pull America out of Vietnam in 1963, the only evidence however being NSAM 263 dated 11th October 1963. JFK was going to, it is believed by a few historians, to pull out 3,000 military advisors, but of course he was assisinated on 22nd November of that year. Now all we know for certain is that President LB Johnson after JFK's death pushed on and dramatically increased the USA military involvement in Vietnam with boots on the ground and mass B52 bombing. What a mess it all became and the embarrassment I witnessed in the retired military of that time.