"And he that hath no sword, let him sell his garment and buy one."
Which brings us to the point. One can't claim to be nonviolent unless one can be violent in the first place. If you, by reason of temperament or inability, are incapable of violence, you have no choice. You are therefore incapable of moral action. Nonviolence means you are capable of violence but in a given situation have decided not to use that capability. The preening pseudo-pacifist unable to resist evil has no more moral virtue than the eager vigilante who has no idea what he's getting himself into when he sees a threat in every group of loudmouthed kids. The truly dangerous person who quietly settles a dispute is the one who's made the moral choice. And if, in some extreme, that person has to confront evil and do violence to end it, well, that's a moral choice too.