An Iraqi child walks next an empty house of a Christian family in Mosul on Aug. 8. The Arabic writing on the wall reads "Real Estate of the Islamic State." The extremist group took control of Mosul, Iraq's second largest city, in June. STR/EPA/Landov hide caption

itoggle caption STR/EPA/Landov

Friar Gabriel Tooma leads a service at the Chaldean Church of the Virgin Mary of the Harvest, in Al-Qosh on June 15. At the time, the Christian village in northern Iraq was taking in those fleeing violence in the nearby city of Mosul. Now the village itself is largely deserted. AP hide caption

itoggle caption AP

Secretary of Defense Chuck Hagel (left) and Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey during a Pentagon briefing on Thursday. Hagel said Islamic State militants in Iraq and Syria posed a threat "beyond anything we've seen." Yuri Gripas/Reuters/Landov hide caption

itoggle caption Yuri Gripas/Reuters/Landov

A picture taken with a smart phone shows Syrian refugees queuing at one of the many UNHCR (United Nations Refugee Agency) registration centers in Lebanon. At the same time that civil wars and the Ebola outbreak are plaguing countries in Africa, Syrian and Iraqi refugees are seeking help from agencies. Joseph Eid/AFP/Getty Images hide caption

itoggle caption Joseph Eid/AFP/Getty Images

Smoke rises during airstrikes targeting Islamic State militants at the Mosul Dam outside Mosul, Iraq, on Monday. Kurdish forces say they have retaken the dam, but the militants insist they still have control. Khalid Mohammed/AP hide caption

itoggle caption Khalid Mohammed/AP

Lincoln, Neb., is home to a sizable community of Iraqi Yazidis — including Ismaeil Khalaf, shown here in his home watching the latest news about the Yazidi crisis in Iraq. Lincoln Yazidis petitioned for U.S. intervention to prevent the genocide of their friends and family. Nati Harnik/AP hide caption

itoggle caption Nati Harnik/AP