We keep arming our policemen with the armor and firepower of military units, but it appears they get none of the discipline, training, respect, and chain of command that military (ideally) has.
I'm going to actually agree with Leshma (ugh) and say we need to make a division of the worst/most violent cops from every major US metro and put them into a real warzone overseas. Maybe that will teach them some humility (or most likely turn into a war crime rape and pillage unit)