No. You can go to college whether you serve a year in the military or not, he can't prevent you from going to college if you're 18 or older.
However, he is under no obligation to pay for your college, unless he has a court ordering him to do so, for example, if he's divorced from your mother and the divorce decree stipulates that he's responsible for your college expenses, or part of them.
He's a Vietnam vet? That would make him pretty old to be a father. Vietnam was over well before I was an adult, and I'm 51. He's in his 60s, and has a teenage kid?