I am more cynical. I think using cruise missiles on Assad was collaborative effort with Russia. Putin lost control of Assad and this is a step to bring him back in line. You might think poorly about Russians, but chemical weapon use is a big No-No for them. Russians finished decommissioning their own arsenal in 2016.
Why I think this was coordinated with Putin. First, Russians were given advanced warning and they chose not to activate AA defenses. Second, US used old missiles that were likely to be replaced by new tech. Third, Assad embarrassed Russians who guaranteed his compliance in 2013.
Russia was supposed to be the Guarantor of the removal of the Chemical Weapons. This again is a stain on them and to believe Russia has destroyed their whole stock pile is naive. I bet North Korea doesn't have any Nukes either... nor is Iran trying to get a Nuke. I have 4 guns but you will only see 2 can you find the other two? I'm gonna bet that's a no because I don't want anyone to find them but me... see how that works? You think a countries will simply give them up with no Guarantee . We already have the answer from Syria with the gas attack.