Free Syrian Army fighters run behind sandbags in Daraa Al-Mahata, in southern Syria, on Jan. 21. Many moderate rebels joined the uprising to fight against President Bashar Assad, but the U.S. plans to train them to fight the self-proclaimed Islamic State. Wsam Almokdad/Reuters/Landov hide caption

itoggle caption Wsam Almokdad/Reuters/Landov

Father Najeeb Michaeel shows off one of the many Christian manuscripts he saved from Iraq's Christian libraries. Alice Fordham/NPR hide caption

itoggle caption Alice Fordham/NPR

Allison Begalman, a student at the University of Southern California, wears goggles and headphones to experience a virtual mortar strike on civilians in Aleppo, Syria. James Delahoussaye/NPR hide caption

itoggle caption James Delahoussaye/NPR

A passerby watches a TV news program reporting two Japanese hostages, Kenji Goto, left, and Haruna Yukawa, held by the Islamic State group, in Tokyo, on Friday. Eugene Hoshiko/AP hide caption

itoggle caption Eugene Hoshiko/AP

Israeli Prime Minister Benjamin Netanyahu will address a joint session of Congress about Iran on March 3. The White House was not consulted on the invitation. Oded Balilty/AP hide caption

itoggle caption Oded Balilty/AP

Saudi Arabia's King Salman, who assumed the throne on Friday, is shown at the G20 conference in Brisbane, Australia, on Nov. 15, 2014, when he was the crown prince. His succession went smoothly, but the new monarch faces a region in turmoil. Pablo Martinez Monsivais/AP hide caption

itoggle caption Pablo Martinez Monsivais/AP