The CIA -— That pied on him? are you nuts? They sucker him in because he is STUPID!!
I'm not even saying that Trump believes the CIA, but if the CIA is telling you with absolute certainty that an attack happened, then as President he can't do nothing after he criticized Obama for not following through on the "red line" threat. The left and right wing would be attacking him, including the Freedom Caucus types.
Assad will lose his airfield, though I have a sinking suspicion they received advanced notice of the attack, and that is why US officials are saying "no people were targeted," because they were allowed to evacuate before hand.