Is it ever okay to kill someone else if it was your job to do so.
Although, the question isn't quite sharp enough, since presumably you have chosen this job, and so you have chosen to put yourself into a position where you would have a measure of legal protection or feeling of justification for killing. A draft is no exception to this, since you have chosen to comply. Never mind whether others think it is justified or not. Whether it is or isn't won't have anything to do with that.
Personally, I think killing in self defense or rushing to the defense of others is justified. If my friend was being raped or beaten and I was physically able to kill her attacker, I think I would do it without any hesitation. Along the same lines, if I consider the reasons for a war to be sound, I am not morally opposed to killing for those specific reasons (ie: defending one's country against invasion.) However, if there is any situation even within war where killing can be avoided, I think it should be.
I think I agree here. The beautiful thing about self-defense is that it does not require killing, and if you can avoid killing, then taking the extra step to kill or failing from trying to refrain from killing appears only as a kind of unjustified and unnecessary vengeance. Anger does not really solve anything. Determination, sure, but not anger, and this is an easy point to agree on. It only serves to deteriorate our own sense of humanity.
What is right when it comes to defense? I don't know. Freedom always came from struggle. It was never just given because it couldn't be. The "just given" was always the opposition to freedom. The "just given" can only appear as an obstacle and a limitation because it is foreign exactly because it appears as just given and not as something derived from ourselves. So freedom arises only from our active assertion of it. And this is necessary, but does this action require killing? Jesus asserted perfect freedom exactly by not killing, so maybe not. Perhaps in every violent revolution are already the seeds of the next tyranny. And who does not fight because they do not feel threatened?
Still, even without feeling threatened, maybe it is right of you to prevent someone from taking your life by killing them if it comes down to it. Are we not quite justified in our will to live EVEN IF we are not attached in a clingy way to our own life? The order of the universe is for you as a finite being to perish, but is it not also that its finite members should strive to live because of their value for life and for their will that their unique will be represented in the grand will of the universe? This seems reasonable to me. If so, then it would seem that Jesus's lesson is not to deny ourselves and give ourselves up, at least not in the entirety, but that this message is absorbed within a greater one, which includes this aspect, but includes also the natural affirmation of life which finite life is filled with. So, we struggle to live, because of our value for it, and our accepting the inevitable outcome that death will take us does not appear to conflict with this, because it is in the scheme of the universe for finite life to struggle for its preservation, and so we are at every point obeying the grand will of the universe. Our struggle to live is almost a kind of play life makes of itself out of its enjoyment of itself. In this sense, struggle is never out of desperation, but it is the very stuff of life which makes it what it is, and gives it itself. Life resists itself. Love is resistance in a way ...