Kill Assad and see what happens...
We already know what will happen: they will go after our head of state.
Kennedy and the CIA tried all sorts of bizarre ways to assassinate Castro: exploding cigars, poisoned wet suits --- Castro got mad.
And had Oswald kill Kennedy. Castro is not a good head of state, but was always way more effective than any of our presidents, danced rings around them.
As soon as Kennedy was assassinated, Congress voted very publicly not ever to try to kill heads of states again. They knew. You can look it up, but I remember.
Besides, killing Assad isn't our war aim.
Our war aim is to show that we are serious that chemical weapons are a no-no. And that when we say they are not allowed, WE MEAN IT.
We won't blow up Assad; we'll blow up something else. Airfields and their air defense would be interesting.