Well could you? Is it something which you'd need to be able to justify to yourself and others or would you require the sanction and support of an authority? What would that authority be if you answer this question that way? Or alternatively would you sacrifice yourself before you woud kill another and why would you do that?
I think one of the most powerful examples of this dilemma or question that I can think of was watching the film The Mission, two jesuits in a former slave plantation turned intentional religious community are confronted by the fact the slavers are descending upon them to annex or kill off the settlement.
They both know they are going to die, one dons his battle gear and goes out to give vane fight and die that way another goes out and leads a peaceful procession and is killed in a hail of shot. I remember an actual Jesuit priest who was watching this film with myself and my friends at the time asking us (or us asking him, I'm not sure it was a while ago) whether the example of the one or the other would be the one which we would follow.
I was sure at the time that I would give fight, no matter what, if its a foregone conclusion then make it as difficult for my foe to subdue me as possible. I'm still strongly inclined to think this yet. Although he said that he felt that way when he was a younger man and wouldnt give the same answer at the age he was now (I think still younger than forty) and that's always made me wonder.