I'm going to adopt a wait-and-see approach on this one.
As long as he stops here - with a single strike against a specific target suspected of carrying out the sarin attack, in the dead of night to minimize even Syrian casualties, with an hour's notice to the Russians to get out of the way - then it might be part of a fairly reasonable carrot-and-stick approach against specific war crimes. In retrospect, Obama would have been well-served by doing the same sort of thing in 2013.
If, on the other hand, he continuously (past Tillerson's meeting with Putin) presses for Assad's ouster in a continuation of Obama-Clinton policies, launches more airstrikes, attempts to impose a 'no-fly zone', channels arms support to 'moderate Syrian rebels', or anything like that, then the neocons/liberal interventionists (same goals, different justifications and party labels) have taken control of him, and the new boss will be the same as the other candidate for new boss, and worse than the old boss.