Quote from Peter Hitchens UK journalist:

"Do we even know that Assad used chemical weapons? I have actually read the reports of the last such alleged attack in Khan Sheikhoun a year ago, and they prove nothing. In fact, they are quite fishy. At the time of writing, I have yet to see a British or US media report on this alleged attack from closer than Beirut, 70 miles from the scene. Many seemingly confident and graphic accounts come from Istanbul, 900 miles away, or from London or Washington. Where are they getting their information from?

Here's a clue. The Saudi-backed faction in control of Douma at the time of the alleged attack, Jaish al- Islam (the Army of Islam), were themselves accused of using poison gas against Kurds in Aleppo in April 2016. They are not especially nice. Their other main claim to fame is that they displayed captured Syrian Army officers in cages and used them as human shields.

They have spent several years indiscriminately shelling Damascus from Douma, having taken the local inhabitants hostage, and then squawking about war crimes if the Syrian government hit back at them, which it did much as the Iraqi government (our friends) did to Islamic State in Mosul and Fallujah"