A team of international chemical-arms inspectors arrived in Damascus on Tuesday to begin destroying Syria’s arsenal—the first time the organization has been asked to scrap chemical arms during a war. What’s more, Syria’s foreign minister, Walid Muallem, said that seven of the 19 declared chemical-weapons sites are in active combat zones. Syria is believed to have more than 1,000 tons of sarin gas, the deadly nerve agent used in an August 21 attack that killed an estimated 14,000 civilians. Under the agreement by the U.S. and Russia, the inspectors will destroy all the equipment used for mixing and delivery by November. The whole arsenal is supposed to have been dismantled by next year.