4,500 U.S. troops died in Iraq, and countless more returned home with physical and psychological wounds they—and we, as a society—will deal with for the rest of their lives. As a nation, we have sunk over one trillion dollars into Iraq so far— one trillion dollars you see missing every day in unpaved roads, underpaid teachers, and the social services our congressional leadership tells us we don’t have the resources to fund, writes Andrew Exum.