Trump stated that he's smarter than all of the generals.
For four years Trump wanted nothing to do with Syria and stated that Obama should stay out. Then during his campaign he said Obama was weak because he didn't intervene. Then as recently as last week Trump and his administration articulated that the US needs to stay out of Syria and to let the people of Syria determine al-Assad's fate. Now Trump says that the gas attack has changed him.
Changed him to what?
No matter what he attempts to blame on Obama, Syria gives him the chance to prove it.