If we don't plan to use our military that way, then we should not use our military at all -- send the freakin' Peace Corp.
The U.S. doesn’t engage in those kinds of military campaigns anymore because we are now a colonial power, not a free nation. It makes no sense to destroy an enemy nation’s infrastructure and kill hundreds of thousands of its people if the whole purpose of going to war in the first place is to build and prop up that nation up as a trading partner.