A health worker administers polio vaccine as part of a UNICEF-supported campaign in Damascus. Aid agencies sometimes have to negotiate with rebel groups and work in dangerous situations to immunize vulnerable children. Omar Sanadiki/AP hide caption

itoggle caption Omar Sanadiki/AP

A woman drives a car in Saudi Arabia on Sunday. Saudi Arabia is the only country where women are barred from driving, but activists have launched a renewed protest and are urging women to drive on Saturday. Faisal Al Nasser/Reuters/Landov hide caption

itoggle caption Faisal Al Nasser/Reuters/Landov

Secretary of State John Kerry, shown in Jeddah, Saudi Arabia in June, has acknowledged the recent tensions between the U.S. and Saudi Arabia, two countries that are normally close allies. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

Children play at the Zaatari refugee camp in Jordan, where more than 120,000 Syrian refugees live. Roughly two-thirds are kids, many of whom have been traumatized by the violence in their homeland. Cassandra Nelson/Mercy Corps hide caption

itoggle caption Cassandra Nelson/Mercy Corps

Syrian youths line up for food distribution in the Maiber al-Salam refugee camp in northern Syria, near the border with Turkey. The U.S. government has provided more than $1.5 billion in aid to Syrians since the uprising began in 2011. Dimitar Dilkoff/AFP/Getty Images hide caption

itoggle caption Dimitar Dilkoff/AFP/Getty Images

Smoke from heavy shelling rises above buildings in Dara'a, Syria, on Aug. 28. Ugarit News/AP hide caption

itoggle caption Ugarit News/AP

A Free Syrian Army soldier stands on a Syrian military tank in front of a damaged mosque in the Syrian town of Azaz in September 2012. A different rebel group, an al-Qaida offshoot, took over the town on Wednesday. Hussein Malla/AP hide caption

itoggle caption Hussein Malla/AP

Syrian refugees wait in Beirut before a flight to Germany on Wednesday. More than 100 Syrians were on the flight, the first mass relocation program for Syrian refugees. Germany has agreed to take in 5,000 of them. Nabil Mounzer/EPA/LANDOV hide caption

itoggle caption Nabil Mounzer/EPA/LANDOV

A rebel fighter inspects purchases made by civilians as they cross through a building near the front lines in Aleppo, in northern Syria, on Monday. The city has been divided for more than a year, with the rebels holding the eastern part and government troops holding the west. Reuters/Landov hide caption

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Mohammed al Hariri is known as the mafia don of the Zaatari Refugee camp. He is the man who gets things done. Peter Breslow/NPR hide caption

itoggle caption Peter Breslow/NPR

Free Syrian Army fighters after a battle against government troops in Zaizoon, near Dera'a, on Feb. 16. Shaam News Network/Landov hide caption

itoggle caption Shaam News Network/Landov

Refugees at the Zaatari refugee camp in Jordan try to squeeze on one of the buses heading back to Syria. Syrian refugees have been coming to Jordan for two years, but some are now starting to head home. Peter Breslow/NPR hide caption

itoggle caption Peter Breslow/NPR

Jordanian protesters chant slogans against corruption during a March 15 anti-government demonstration in Amman. Jordanians have held Arab Spring-inspired protests since 2011, demanding political reforms and anti-corruption measures. The protests have been peaceful. Khalil Mazraawi/AFP/Getty Images hide caption

itoggle caption Khalil Mazraawi/AFP/Getty Images

Refugees fill cans with water inside a camp in Baalbek, Lebanon, for Syrians who have fled the fighting in their country. Spencer Platt/Getty Images hide caption

itoggle caption Spencer Platt/Getty Images