I think the whole scenario about chemical
weapons is just to get the public behind the US
attacking Syria. It is rediculous to blame Assad
of using chemical weapons while it is not clear 
if the opposition did not use them and 
Saudi Arabia an allay of the US gave the rebels
such weapons.
It is ridiculous to justify an attack on Assad
while the opposition he supports in Syria are
recognized terrorists. 
But I assume Obama will note  have problems to
construct evidence for the use of chemical
weapons in Syria and use it as a reason to attack.

 Obamas war is rather business and not about the
 use of chemical weapons. The US wants to have
 advantages of their strong military. That is what
 countries with strong military often want. And
 then they seek a reason to go to war to go for the
 prey they are after.
The people around the world have to decide if
they want to accept that or try to.prevent such.