The Emerging Trump Doctrine: Don’t Follow Doctrine

The rules didn't change. Poison gas has been outlawed since the Geneva Convention. Since when do we have to warn a murderous dictator about anything?

If you want someone to do something "or Else" you have to FIRST make sure that the something and the "or else" are clearly known to both parties. Being unclear on what your goals are is a major weakness that trump uses as a default position.

Obama did that, IIRC, by laying down his "red line" regarding the use of chemical weapons. Assad and Putin both put forth declarations that such weapons had been disposed of, and then Assad proved himself to be a liar by using those weapons. Obama, predictably, did nothing, proving himself to be weak once again. The current President reacted to another such attack by destroying the base from which it had been launched. Now that it's done, you are whining about it. I must presume that you preferred Obama's weakness in such matters. Use of chemical weapons is a violation of international agreements. Retaliation for such violations should be the default position of any signatories to those agreements.