The first two American F-35A Lightning II fighter jets land in Leeuwarden, The Netherlands, on May 23, 2016. (Photo: EVERT-JAN DANIELS/AFP/Getty Images)
A French police officer stands guard by Saint-Etienne-du-Rouvray's city hall following a hostage-taking at a church in Saint-Etienne-du-Rouvray, northern France, on July 26, 2016 that left the priest dead. (CHARLY TRIBALLEAU/AFP/Getty Images)
Iraqi Christian children, who fled the violence in the Nineveh province, attend a mass with their mothers at a chuch in Dekwaneh, east of the Lebanese capital Beirut on March 21, 2015. (ANWAR AMRO/AFP/Getty Images)
The graffiti tagged on the wall of a house in the Iraqi city of Mosul, July 26, 2014. It reads in Arabic : 'Real estate property of the Islamic State (IS)'. (AFP/Getty Images)