The very first questions should sound like this:
are we sure that Assad used sarin on the rebels or do we rely on informations from groups near to the islamic rebels, like the white helmets, who are known to lie about everything?
Why would the US bomb a government airbase exactly the same time when the so called rebels start an attack against Assad forces and they will need this very same airbase to fight those rebels?
Beside Assad who has plenty of sarin and who would like to have the USA to enter the war in Syria, besides Hillary and her cohorts?
Answer 1: It was never proved who lauched the giftgas attack during 2013 that killed over 1,000 people and probably this one also never will be proved without a doubt. Falseflag operation are more than possible, yet the whole world very conviently charge Assad.
Answer 2: Was this incident very carefully coordinated, so the world blames Assad and the US can destroy his fightingpower to aid the US backed so called rebels, in truth US and Saudi backed and supplied foreign fighters, as most of them are not even syrians? This is a question and also a reply to think about.
Answer 3: Beside Assad, Turkey and Israel could have dropped the giftgas, as they both have a dire desire to have the US in that war and both have plenty of such weapons, in addition to other unsaviory actors in that drama.
It is an old truth, keep generals away from politics, as they are trained to solve every problem with force! Trump has just too many generals in his team, so I am afraid this may just be the beginning of new and bloody wars.