Were there alternatives to the American military build-up in Vietnam?

There are ALWAYS options in life. We could have just let North Vietnam take over South Vietnam. We could have helped South Vietnam for a year or two and then just left (departed). We could have just let the US advisers stay there without regular US troop involvement. We could have stayed there and continued on, and on, and on, through President's Carter, Reagon, Bush (Senior), Clinton, and onto today with Bush (Junior). As it was, we began with President's Eisenhower in 1955, on through Kennedy in 1961, up through Johnson in 1965, and then finished it up with Nixon by 1973. That was enough!