Seems that talking loud so you don’t have to wield the big stick is an attempt to stay out of a war - else a LOT of chemical weapons might be used in a lot of places around the world.
If you are going to pretend that the “chemical weapons” in Syria haven’t mostly been our own false flags.
This bogus scheme has been used several times in Syria. Announce there could be a “chemical attack by Assad”, then stage it.