I'll start with Putin's and Assad's initial proposed compromise. That compromise dealt with Assad getting rid of his chemical weapons. But considering both Putin and Assad have stated, it's more likely the rebels used them to draw their Patron the U.S. in, Why didn't they include in their proposed compromise, a condition that the rebels give up their chemical weapons too? The only reason i see, Putin and Assad know the rebels don't have chemical weapons.
Another reason i say Assad used chemical weapons on his people. In Assad's interview he stated, "it has not been determined YET, that he used them". Was he being sarcastic? If he wasn't, wouldn't you expect him to say, they want find any evidence, because we didn't use them?
This is not about whether i want the U.S. to attack or not, i am simply raising a point of view who i think is lying and why. We now have a chance to get rid of Assad's chemical weapons through negotiations which is good, but i do think Assad used them and to avoid a U.S attack, weighed the advantages and disadvantages of using them again, and concluded it's best to get rid of the chemical weapons. After all, there is no proof rebels used them and there is no proposed compromise that include taking chemical weapons from the rebels. Why not? Wouldn't taking chemical weapons from the rebels be the first consideration, considering all the talk about them being Al Qaeda and they could end up, or is already in the hands of so called terrorist and actually threaten any country, including us? Conclusion due the the actions and words of both Assad and Russia, they know the rebels didn't do it, because they didn't have any.