Concerns about being a fighter pilot

I had a talk with my dad about being a fighter pilot a few days ago and he said that he didn't agree with my decision. He stated that being a fighter pilot requires taking lives and that he would not support me in this because of the moral lines, and that we are not the kind of people to do this. I really really want to be a fighter pilot and cant stop thinking about it, but I also don't want to destroy my relationship with him. What do I do? I kind of view the killing part as defending a country and imagine I would have to kill people like the terrorists behind 9/11.I wouldn't enjoy it, but I would do it if ordered to, and its not enough to deter me from wanting to be a pilot as morally I feel like these people do kind of deserve death. (obviously if its innocent civillians thats a different story)