A team samples the impact site of a cylinder that contained chlorine gas, which was dropped on a field in the rebel-held Syrian city of Saraqeb on Feb. 4. OPCW hide caption
Syria civil war
Mohammad Javad Zarif, Iran's Foreign Minister, in New York City on April 23, 2018. Elias Williams for NPR hide caption
A crowd in central Damascus waves flags and portraits in support of President Bashar Assad on Monday, two days after the U.S., Britain and France carried out airstrikes. The photo was released by the official Syrian news agency SANA. AP hide caption
Displaced Syrians, who fled their homes in the city of Deir ez-Zor, carry boxes of United Nations aid at a camp in Syria's northeastern Hassakeh province in February. Delil Souleiman/AFP/Getty Images hide caption
Syrian President Bashar Assad, center, speaks with Syrian troops in newly captured areas of eastern Ghouta, near the capital Damascus, Syria, Sunday. Al-Ikhbariya TV broadcast images of Assad surrounded by soldiers on a street in eastern Ghouta, where a Syrian offensive has been underway over the past month. It was not clear where in eastern Ghouta Assad was. Syrian presidency Facebook page via AP hide caption
Caleb Stevens (fourth from left) in Raqqa, Syria, with other members of his unit. Stevens, a 23-year-old from Michigan, traveled to Syria to fight with the Kurdish People's Protection Units or YPG. Courtesy of Caleb Stevens hide caption
Syrian Army forces say have captured Mesraba and advanced into nearby farmland. It would be significant strategic victory for the government in wresting control of Douma from Islamist insurgents. AP hide caption
A lightly wounded Syrian girl is carried by a man at a makeshift clinic following Syrian government bombardments in Douma, in the besieged Eastern Ghouta region on the outskirts of the capital Damascus on Thursday. Hamza Al-Ajweh/AFP/Getty Images hide caption
Syrian pro-government forces patrol in the eastern city of Deir el-Zour in November. AFP/Getty Images hide caption
A volunteer rescue team attempts to put out a fire in the Syrian city of Maaret al-Numan, in the rebel-held province of Idlib, on Wednesday, following airstrikes reported by a U.K.-based monitoring group. Amer Alhamwe/AFP/Getty Images hide caption
Looking at the damage in the aftermath of an explosion at in a rebel-held area of the northwestern Syrian city of Idlib on Monday. Omar Haj Kadour/AFP/Getty Images hide caption
Pieces of cloth that Mansour Omari and other inmates at a notorious Syrian prison used to document the names of the "disappeared" held with them. They made ink out of blood from their bleeding gums and rust from the prison bars. Dylan Collins/Courtesy of the U.S. Holocaust Memorial Museum hide caption
A man looks out of a damaged building in the mountain resort town of Zabadani, Syria, in the Damascus countryside, in May. The U.S. and Russia announced a new cease-fire deal on Friday. Hassan Ammar/AP hide caption
A picture taken on April 4 shows destruction at a hospital room in Khan Sheikhun, a rebel-held town in the northwestern Syrian Idlib province, following a chemical weapons attack. Omar Haj Kadour/AFP/Getty Images hide caption
Mouaz Moustafa has spent years advocating on Capitol Hill for the United States to get more involved in Syria. Polly Irungu/NPR hide caption