The military has a military mission, but over the years, the non-military, feel-good social engineering has absorbed entirely too much of the military budget.
Plus, the pork of earmarks has awarded money to congressional favorites without consideration for the needs of the warfighter.
I agree. I think the military exists to kill people and break things. If we want to engage in "nation-building" then we ought to send the Peace Corps -- and if the situation on the ground is too dangerous for the Peace Corps, then we shouldn't be doing any nation building.
Also, the acquisitions environment in the military is ridiculous. Everything costs more than it should. It pains me to say it, but there is a lot wrong with DoD. Less money would probably make for a more efficient and effective military.