I recently started rereading Normal Mailer's Harlot's Ghost.
Like American Tabloid
it's fiction based on Freedom of Information requests both authors sent out about the CIA and FBI activities during the 1950s and 1960s.
Nobody ends up looking particularly good in either tale.
In both stories the CIA people themselves never really do anything. Instead they come up with schemes and then employ local talent on a freelance basis to pull it off.
This explains a lot about the the CIA's successes and fuck ups during that time. In places where the hired thugs were reliable (West Germany, South America) the CIA did pretty well. In places where the talent was unreliable (Cuba, most of Asia) they did fairly poorly.
In any event they were hardly James Bond.
Both books also are pretty negative about JFK. The authors see him as a good looking, but malable fuck up, who didn't trust the CIA at all, and didn't understand that Hoover and most of the FBI didn't give a shit about stopping organized crime.
(In both of the books there are references to JFK being called "2.5 Minute Jack" by Hoover, because that's the average amount of time he lasted in the sack according to FBI surveillance audio.)
Where they differ is on Vietnam. Mailer seems to be arguing that Vietnam was the CIA's attempt to fuck over JFK and eventually distract LBJ from the agency's fuck ups in Cuba.
American Tabloid takes a more cynical interpretation. He thinks that with JFK and LBJ cutting the CIA's budget, or at least giving it more scrutiny, the CIA needed a way to raise a lot of black market cash for themselves.
Vietnam was perfect, because they could easily manufacture millions of dollars of heroin there. They had a built in distribution system, because the mob hated JFK and and LBJ. The mob also needed to raise extra cash because they'd lost a ton of money when they got kicked out of Cuba and had yet to make a reasonable return on their investment in Las Vegas.
Either way, both authors argue that the CIA wasn't really concerned about the Vietcong, they just needed some kind of distraction from what they were really up to.
Anyway, I highly recommend both books. I don't endorse either author's interpretations 100 percent, but they are food for thought on American history.