Was it revenge? Yesterday, a Russian military helicopter was shot down near the town of Saraqeb in northern Syria, where rescue group Syria Civil Defence reports today that a helicopter has dropped barrels containing suspected chlorine gas. It’s unclear who was behind the attack, which has affected at least 33 people. Previous investigations have linked chlorine gas attacks — a practice banned by international law — to Assad’s regime. But with rebels and government forces still fighting in nearby Aleppo, inquiries may be slowed.