A volunteer at a Christian church in Qosh, Iraq, loads aid onto a handcart Monday for delivery to displaced Shiites who are sheltering there. Alice Fordham/NPR hide caption

itoggle caption Alice Fordham/NPR

Iraqi Shiite volunteers with the Labayk ya Hussein Brigade take part in a training session in the holy city of Najaf in late June. Clerics in the city called for Shiites to step forward and fight the Sunni group formerly known as the Islamic State of Iraq and Syria (which now calls itself simply the Islamic State). Haidar Hamdan/AFP/Getty Images hide caption

itoggle caption Haidar Hamdan/AFP/Getty Images

A leading Sunni tribal chief, Sheik Abu Ali al-Jubbouri says he misses former Iraqi leader Saddam Hussein, who favored his sect. Hussein Malla/AP hide caption

itoggle caption Hussein Malla/AP