The argument is that the military is disposed to killing and breaking things, and so you need a softer touch to win hearts and minds.
Although warfighting and peacekeeping clearly require different tactics, rules of engagement, and outlooks, I disagree strongly with the notion that we must have another gentle force dressed like soldiers to carry out peacekeeping.
Any type of force trained to be compassionate will falter when the enemy decides that it needs to stop the hearts and minds of the locals from going to our side. Then Americans in military uniform--but not actual soldiers--will die in sizable numbers because they can't stand up to the violence that suddenly springs on them. It will be a disaster and CNN will film the local thugs dragging camo-clad American corpses through the streets.
Properly trained, I hold that any good soldier or Marine can be a good peacekeeper and nation-builder. There can be a problem transitioning from peacekeeper to fighter and vice versa in the moment of transition, but they can transition with good leadership. And time. Especially when going from peacekeeper back to warrior, training is needed to break bad habits of restraining violence.
Strategypage discussed the 8,500-strong French Foreign Legion in this regard:
The Legion attracts a lot of men who have served in their foreign armed forces (usually in the infantry or commandoes), and are looking for more excitement, and something different. The Legion can provide it, because this outfit is France’s main intervention and peacekeeping force.
One small force used for both types of missions. It is lethal and flexible enough to handle both missions.
I don't want pseudo-s0ldiers who will fail and die when pushed too hard. Well-trained infantry and Marines can do any job we give them with proper training, euqipment, and leadership.
If you really want troops to police locals without drawing too heavily on the conventional forces of our military, expand the Military Police. There won't be a shortage of security missions for these troops for the next generation even when they aren't in foreign cities policing locals to win their hearts and minds.
