Could you you kill a person? Could you both mentally and physically bring yourself to end a life? And if you did, would you be able to live with guilt over it, no matter what sort of person you killed?
I would never be able to do it, I wouldn't be able to live with guilt, and I deeply fear if it will have consequences in the afterlife (not trying to start religious debate).
No matter what side they're fighting for, or whether they're a good or bad person, I just wouldn't be able to do it.
Also, by 'could' I mean, could you make yourself do it? As in, WOULD you?