Really, Heidi, of what value is an agreement signed under duress?
All you are doing is setting Assad up to be punked by the AlQaida elements there who only have to stage another 'attack' to get free air cover.
Simultaneously, you doom a few hundred average slobs (or maybe just Christians) there to be the subjects thereof. A few head wraps later, and some time with a video camera, and AQ and the MB have air support.
These people are terrorists, and a few innocents (or a few hundred) mean nothing to them if that is all it takes to achieve their goals.
Gee, such a decisive statement. And in all of this, no one in the Obama Administration has gone on the record to state unequivocally that the Syrian government was responsible for the gas attack. So let's say Assad signs the treaty and takes concrete steps to comply, yet the gas attacks continue? Then what? Or better yet, what if Obama fails to submit his long term policy on Syria just as he has failed to do on every other long-term commitment he had?