Basically what he's saying is he'd rather have the teachers suffer the trauma of seeing lots of kids killed than have them have to deal with the trauma of killing someone. It that makes sense to you, you just might be a liberal. No one wants to take a life, but when faced with a choice between killing someone intent on killing lots of people, including you, or standing there and watching a lot of people die, we have a word for that - it's called coward.
I've never killed anyone, and I hope I never have to, but if I do, I'm pretty sure I can live with myself and deal with the mental trauma. I know men who have killed in combat and have no problem living with it. When you life is on the line, you do what you have to do so you can go home.
