...the 2nd phase of the nearly continuous, with a 20 year tenuous pause, World War that began in 1914.

Then there was the invention of the "missile gap" that JFK used to put himself in the White House. The American public in the 1960s was proportionately less educated than the public today, although as is obvious from Trumpism, ignorance is still a powerful force in our political life. In those times, 20 years after the Manhattan Project achieved its goals, it was widely believed that intellectuals were competent to save the world.

John Kennedy, who I don't think had as powerful intellect as is sometimes attributed to him - although he was excellent at reading and delivering Ted Sorensen's text as speeches - having hung out at Harvard, played on the fascination with academic intellectuals, who may have been good at understanding some things, but far more narrow in others.

On reflection, I think Lyndon Johnson, Vietnam aside, was a great man, and I have never felt that Vietnam, such as it was, was a function of him paying too much attention to these narrow "great minds." He might have profited by listening more carefully to Rayburn.

is that the Asian desk of the State Department was effectively hollowed out by the McCarthyism of the 1950s.

Those in the Department who had expertise in, for instance, Chinese politics and especially the realities of the Chinese Communist takeover were hounded out of government by all the "soft on Communism" and "I have a list of 50 card carrying Communists in the State Dept," BS. This was also true of anyone there with actual experience in Vietnam or "French Indochina."

Not that the expertise on Indochina was all that deep to begin with. Halberstam points out that when Kennedy took office there wasn't a single person in the State Department who could speak or read Vietnamese. But certainly anyone there who saw what was happening in Vietnam as a nationalist struggle against colonialism, as opposed to being a part of some vast "international Communist conspiracy," anyone who had a more nuanced view of the politics in the region was out on their ear by 1960.

As a result of all this, the highest levels of the Dept. were filled with the likes of Dean Rusk, hardly an original thinker and known for playing it safe when it came to the "Communist threat" in Asia.

All this contributed to the woefully flawed advice LBJ received from his aides.

I agree with your assessment of LBJ, by the way. I forget who said it, but someone at the time remarked that "Johnson's problem isn't that he's uneducated. It's that he thinks he's uneducated," or words to that effect.

...is that he was very close friends with the Kennedy's, dated JFK's sister, and was Godfather to one of RFK's children; if I recall correctly, it may have been "brain worm" RFK Jr.

JFK was the only Democratic Senator not to vote to censure McCarthy, not that he voted against censure. He conveniently had himself hospitalized with back pain during the vote.