I've spent the day cogitating on this, in between earning money
I don't know the reasoning, the "chemical incident" looked totally faked to me as a piece of propaganda and Assad certainly had no reason to antagonize the US when only days earlier Sec. of STate was saying nicee things. It is personnally dispiriting to see Trump fall for it (or not) and to ruin a rapprochement with Russia. I can only enumerrate plusses and minuses.
Plus:
Trump showed tough very early, no national leader will take him lightly, which is good.
He would have impressed the Chinese President with whom he dined later.
He pleased Sadis, Ergoden of Trukey and other supporters of ISIS and Al Qaeda.
Minus:
Loss of his supporters.
Ruined Russian rapprochement
So is Trump gullible and stupid? He got all the usual suspects, including Canadian Twerp Trudeau, all in line singing from the same song book. It looks like the beginning of another NATO make-work project, just like Sarajevo and Kosovo, where we also bombed the wrong people due propaganda.
Or was this like Clinton lobby a hundred cruise missiles into Afghanistan, just for show?