Please. More knowledge, less generalized hyperbole. 

US intervention in Vietnam had far more to do with adherence to an overly simplistic domino theory than it had to do with some ill-defined, amorphous fascist plot.
As was typical of the time, they saw everything in simple us vs communism terms. The US' failure to identify and respect the Vietminh as primarily independence-seeking nationalists, early on,  as opposed to a hard core USSR proxy movement (where they got pushed later) is the true irony and tragedy of that war. Well, the "American War" as the Vietnamese call it, distinct from the Japanese and then French conflicts which preceded it. 

I recommend "Vietnam: A History" by Stanley Karnow and "A Bright Shining Lie" by Neil Sheehan, both Pulitzer Prize winners.