U.S. soldiers stand at a checkpoint around Lakokhel camp in Afghanistan in 2010. Many soldiers return from war suffering from "moral injuries," or dealing with the fact that their sense of right and wrong was violated. Martin Bureau/AFP/Getty Images hide caption

itoggle caption Martin Bureau/AFP/Getty Images

Classrooms across Gaza are crowded with as many as 50 or 60 students, principals say, as dozens of school buildings have been destroyed or damaged, or are still housing people who lost their homes. Emily Harris/NPR hide caption

itoggle caption Emily Harris/NPR

Syrian Foreign Minister Walid Moallem (left) at the peace talks in Montreux, Switzerland, on Wednesday. Gary Cameron /Reuters/Landov hide caption

itoggle caption Gary Cameron /Reuters/Landov

Some of the destruction at the scene of Friday's car bombing in Beirut. AFP/Getty Images hide caption

itoggle caption AFP/Getty Images

Troops sent to South Sudan by the U.N. watch as men walk to a camp for refugees near Juba, the nation's capital. James Akena /Reuters /Landov hide caption

itoggle caption James Akena /Reuters /Landov

In the northern Syrian city of Aleppo last month, there was a class about how to protect against chemical weapons attacks. J.M. Lopez/AFP/Getty Images hide caption

itoggle caption J.M. Lopez/AFP/Getty Images

At the White House, President Obama and his advisers continue to work to build support in Congress and among allies for striking Syria. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

British Prime Minister David Cameron, who says it is time for the U.N. Security Council "to live up to its responsibilities on Syria." Stefan Wermuth /Reuters /Landov hide caption

itoggle caption Stefan Wermuth /Reuters /Landov

Ammunition was stacked up Saturday in an area near Damascus that is controlled by forces loyal to President Bashar Assad. Khaled al-Hariri /Reuters /Landov hide caption

itoggle caption Khaled al-Hariri /Reuters /Landov

Gas mask in one hand and rifle in the other, a Free Syrian Army fighter sits inside a house in the city of Homs early Thursday. Yazan Homsy /Reuters /Landov hide caption

itoggle caption Yazan Homsy /Reuters /Landov

Secretary of State John Kerry using his head Tuesday in Kabul, where he met the captain of that nation's women's soccer team. Jason Reed/Reuters /Landov hide caption

itoggle caption Jason Reed/Reuters /Landov