Basic training involves very little training in violence, none of it organized, none of it formal. Unless Penney went into the combat arms, and received further training in a combat speciality, he has no more violent a background than I do.
Basic training was mostly physical conditioning, cleaning things, drinking water, and marksmanship. That last they went to great lengths to make as non-violent as possible (for what I hope are obvious reasons). Out of eight weeks, we got about two hours of desultory introduction to the bayonet, half an hour of desultory fooling around with boffer sticks, and half an hour of desultory review of the Army's half-assed idea of unarmed combat. I spent more time learning how to cope with chemical and nuclear attacks than I did on any of those three topics.