When they make you so survival training they make you kill a rabbit because modern people are so ridiculously disconnected from the roots of their survival that doing such a thing is difficult. They often cannot snap the neck of the rabbit so they begrudgingly try to smash it's head with a rock and fail and the thing becomes horrifically a cared and seizures and screams and the trainee panics. A calm man who knows simply grabs the head and the shoulders and twists in a jerking motion and the thing is done.

Being incapable of killing righteously and correctly causes more suffering than killing correctly.