As a Syrian-American who voted for Clinton, I am incredibly happy that Trump has shown resolve where Obama failed to.
This may not directly cause the downfall of the abominable Assad regime, but at least it will make Assad think twice before using chemical weapons again. Hopefully, it will be followed by safe zones and arming the Free Syrian Army.
It's not Assad using chemical weapons, it's the US backed groups. They launch a gas attack on civilians, blame it on Assad, and it gives them a 'credible' reason to keep trying to oust Assad for the formation of 'Greater Israel'.
Hypothesis: this is a message to Xi and North Korea. Syria is a consequence-free zone. Unless we depose Assad and commit to nation building, this has limited non-humanitarian consequence. Bonus: decisive action right after McMasters reclaims Bannon's NSC seat.
Or it could be a message to Assad to stop using nerve gas.
Just a wild guess.
It would have made absolute zero sense for Assad to use nerve gas. Because the Assad/Russian coalition was already winning and Trump previously stated that it would be up to the Syrian people to choose their leader, i.e.: no more neo-con regime change.
I also believe there is no concrete prove yet that Assad is really behind the nerve gas. And I would be very septic about any proof from the USA (it would need to be really really substantial), because let's admit it: the proof of the weapons of mass destruction in Iraq in the end proved to be false.
Both the USA as well as other forces (the so-called white helmets that have a very questionable track record, Turkey, perhaps even Israel) in the region seem to be very interested in removing Assad, no matter the costs.
We have no security imperative around the use of chemical weapons in the Middle East. Remember, Assad is fighting ISIL. The salvo shows various states the United States is willing to act unilaterally. Knocking out some MiGs is a cherry on top.
Edit: removed hash