A few weeks ago, the US Central Command announced that an air raid had killed an ISIS chemical weapon expert in Mosul. The ISIS operative, Iraqi engineer Mahmoud al-Sabawi, used to work at Saddam Hussein’s chemical weapons program before he joined al-Qaeda in Iraq after the 2003 US led invasion. The idea that ISIS terrorists have access to chemical weapons brings back images of the genocide inflicted on the Kurds by Saddam Hussein in the late 1980’s. The Halabja Massacre killed up to 5,000 and injured between 7,000 and 10,000 more. If ISIS jihadists have a stash of chemical weapons,...