War in Syria: Russia and West clash over Idlib gas attack (part 2)
On Tuesday in Idlib, a province in northwestern Syria, at least 70 people were killed, 20 of them children, in what appears to have been a chemical weapons attack on the rebel-held town of Khan Sheikhoun. Initial reports point to the nerve agent sarin gas. Our panel of experts asks who was behind this attack. What explanations are being put forward, and do they stack up?