Lest we forget it was the Democrats holy figure St. John of Kennedy who first sent advisers to Vietnam in the early sixties. Leftist historians are running with the narrative that if JFK had lived we would of gotten out of Vietnam. All speculation on their part, but this was a war started by a Democrat president.
Then, in 1954, Eisenhower took over with advisors and assistance to the south.
JFK increased the number of advisors dramatically and then, of course, LBJ started with actual ground troops, the first being perimeter protection for US air bases in the south.
In Eisenhower’s defense, he refused to send US forces to intervene in the battle of Dienbienphu. A good general knows you shouldn’t start a war unless victory is a sure thing. That is now considered one of the best things Ike did as president.