Kerry opened his mouth and put both feet in it.
Putin, the wily old dog, saw an opportunity and took it.
This is purely a delaying tactic.
There is no way that Assad will allow a strict and invasive enforcement regime. But he will pay lip service for the time it gives him. He will use this time to regroup and to re-equip. Russia has sent 7 landing ships to Syria, they are not carrying baked beans. The war will be prolonged.
Assad has possibly the biggest chemical warfare stocks in the world. Mustard, Sarin and VX. He has built a huge missile force to deliver this into Israel. Perhaps 2,000 ballistic missiles. He built this force up for deterrence, as a counter to Israeli nuclear weapons. And deterrence has worked. It is probably what has kept Turkey away from involvement in the conflict.
Obama has been shown up as being unfit for office. He is just a glib mouth, not a leader. He is now a dead duck president. The remainder of his presidency will see the ascendency of the powers for harm in the world. Russia, Iran, North Korea. USA has lost all credibility in the world. Undone by Iraq, Afghanistan and Syria. Despite their enormous military power they have been comprehensively outmanoeuvred by Putin at every turn.
In this disaster UK politicians like Blair and Hague have been complicit.