I met them in Sierra Leone. Former rebels, shopkeepers, barbers--now calling themselves Iraq vets. They had been to places like Habbaniyah, Anbar, Haji, on jobs for Pentagon subcontractors. One of them, Jeff Roberts--known as Firefly to the U.S. servicemen in Iraq--told me his story earlier this year, over several sessions of fried chicken and soda in downtown Freetown.

Roberts was one of the tens of thousands of so-called "third-country nationals" who were paid...