It takes hate to kill. The US military and the police know this. Any business requiring killing needs a mechanism to generate the hate.
The police do it with their “bad guy” mantra which is repeated as often as possible. They place criminality outside of themselves. This mental training begins very early in police academy. The military does similarly.
Both the military and police treat their recruits like shit, so that they get pissed off. Recruits learn to hate their superiors and their drill instructors. But under their system, soldiers may only kill with permission, and may never kill fellow military. The hate is created, then is directed at the enemy.
Hate is such a powerful weapon that the USG would like to keep it for itself. The USG has declared a “war on hate.” They’d like hate control, just as there is gun control. There’s a great effort directed so that minos may hate, while whites may not.