"Any battleground is an extremely toxic environment, " said Jean Pascal Zanders, a senior research fellow at the European Union Institute for Security Studies, who specializes in chemical and biological armament.
Jean Pascal Zanders, a chemical weapons expert and a senior research fellow for the European Union Institute for Security Studies, cast doubt on the use of chlorine, saying in an e-mail that one small rocket couldn't deliver the quantity needed to kill 25 people.
"The way Syria configured its chemical arsenal was essentially as a weapon of strategic deterrence, not really to be used on the battlefield, but as an instrument of last resort, " said Mr. Zanders of the EU Institute, likening Syria's capacity to use chemical weapons to how Israel treats its nuclear weapons.