Back in the Eisenhower days a little Asian adventure in Vietnam started the same way. Dribble, dribble, drip, drip,Kennedy, Johnson, Tonkin!
Eisenhower got that line drawn in Korea (it's still in place) and warned the US about the military industrial complex. I suspect he'll go down in history (if there still is a history) as a great president for the transition from post-war wind down to the most successful consumer economy ever on the planet.
Catholic JFK got escalation fever because he wanted to protect the Catholic Diem regime in VN. That's one hypothesis.