One analyst I heard yesterday on NPR, some guy who runs some kind of foreign relations think tank (how's that for credentials? Haha) said that he thought Syria's chemical attack was less of a FU to the world/U.S. than it was a direct affront for the Russians. He thought it was intended to show the Russians that Assad is independent of Putin. He presumed that Syria had an agreement with Russia (since Russia is backing them) to not use chemical warfare and this shows the Ruskies, hey, you guys don't control me.
I found that very interesting.