"After the Vietnam War, all those military academies lost ground because people really disrespected the military," Mr. Trump said. "They weren’t sending their kids to military school. It was a whole different thing, but in those days — 1964 I graduated — that was a very good thing or tough thing, and it was a real way of life at military academy." [...]
"My number was so incredible and it was a very high draft number. Anyway so I never had to do that, but I felt that I was in the military in the true sense because I dealt with those people," he told [the biographer]. [The New York Times]
Trump also said that his time at boarding school provided him with better training than many members of the military. He was never actually drafted to go to Vietnam because he received medical deferments for heel spurs.