The mission of the military is "To close with and capture or kill the enemy." Period.

Combat is the mission of combat troops. Peacekeeping is the mission of peacekeeping troops, who should be trained in that. The US leaders have failed to recognize this again and again; Civil Affairs Units (such as the Military Government units set up in the Philipines and Europe during WW2) should be doing it but are not.

Just another example of piss-poor planning.