One – Dictators around the World, from Burma to Bahrain, from North Korea to Saudi Arabia, will be emboldened to think that they can get away with gassing their populations if their regime comes under serious threat and that the Worldwide community will do a lo of flapping, but ultimately do nothing.
It’s funny how this argument somehow never seems to get made for, say, miltary coups in Egypt.
Of course, Syria itself is a sideshow, a stepping-stone to attacking Iran. If certain elements in Washington succeed in starting a war against Syria, then the attempt will be made to ride the war momentum into an attack on Iran afterwards (as happened with Afghanistan and Iraq).