As for the Russians, their military intervention in Syria has hitherto been highly successful because it has re-established them, at least in the Middle East, as a superpower. If they conclude that Assad was indeed behind the chemical attack – something they currently deny – then they will be infuriated that he has risked so much for so little. The Kremlin will be eager to continue to pursue parallel policies with Washington, something that dates back to 2015 when Obama decided not to oppose Putin’s military intervention on the side of Assad. This was a critical moment in the outcome of the war.
From Trump’s point of view there is a great advantage in any cross words coming from Moscow because they will counter accusations in the US that he is too close to the Russians. Democratic Party and media criticism, based on conspiracy theories claiming that Russian hackers determined the course of the election, will be deflated and Trump will have his first foreign policy success. The missile strike could do more change to the political landscape than in Syria.