If we game theory this out it makes sense. Putin gets out of Syria, Trump gets rid of Assad AND Isis (assuming Russia will be allowed to finish off Isis) and shows he won’t take crap. This was planned - its no coincidence Russia has been backing off support of Syria lately. The gas attack was probably fake to allow this attack.
Trump has proven he is a master of strategy..we should give him the benefit of the doubt. My initial reaction was WTF but after thinking it through it makes sense.
So, following your thoughts, who is left in power in Syria? I’m sure you can see where I’m heading...