It looks like the on-again, off-again US-Russia relationship in the Syrian civil war suffered another painful, if not fatal, blow last week when the United States launched cruise missiles at a Syrian regime airfield in retaliation for a gas attack on Syrian civilians.
The US action triggered a predictably harsh reaction in Moscow, which has been calling for a thorough investigation of the April 4 poison gas attack on the Syrian town of Khan Sheikhoun. The gas attack killed dozens of people and injured hundreds. Syria has denied using chemical weapons in that attack.