"In 1954, the French implored Eisenhower to send the U.S. Navy to rescue Vietnam. Eisenhower refused. He acquiesced in the division of Vietnam into a Communist North and a South informally allied with the United States and sent a few hundred advisors."
If you can believe Wikipedia
http://en.wikipedia.org/wiki/Dwight_Eisenhower
Kennedy was feckless and McNamara was an arrogant know-it-all who was great at counting widgets for Ford but clueless about how to run the military. Johnson was a ruthless politician who got a Silver Star from MacArthur for riding in a jump seat on a mission to New Guinea that was aborted. Combine that with a bunch of suck-up Chiefs who knew what we were getting into but wouldn't confront the President and you got Vietnam.