Dusting off my tin foil hat, I would go with Israel in collusion with the NSA/CIA. They have the most to gain by turning the media against Syria and the technical capabilities as proven with their involvement in stuxnet.
http://en.wikipedia.org/wiki/Stuxnet
You think that Israel wants a war with Syria? Syria could easily turn those chemical weapons across its border. I think Isreal is probably one of the big factors causing US restraint right now.
But my tin-foil hat hasn't been working very well lately so the government radio signals may be blocking me from seeing something.
Things are enough of a powder-key economically this sort of thing to get out-of-hand in a big way.
China and America are co-dependent but at cyber-cold-war. Russia just recently gave the middle-finger to the U.S. with Snowden and we refused to meet with each other. The two primary powers that emerged after the last world war are no longer at the top so there is an open gap for who's next: the U.S. who no one wanted to mess with is overstretched, underfunded, and there is no better president to have at the helm if you want a war with the U.S. than one who has not achieved much militarily other than social reform and withdrawal, is on the edge of economic shambles due to decades of overspending much more than the stock market and media would lead you to believe, and whose party's voting constituents aren't in favor of a war, and Russia, who turned into a mafia-run state with former KGB at the helm that are unable to elicit much nationalism- much less a military power it used to be, doing the equivalent of selling its military assets on ebay for years.
Mass executions from chemical attack or otherwise are not the reason we are getting involved. This is a power struggle. Some big players (Clinton comes to mind) in U.S. Democratic party are set on cleaning up the Iran/Syria/Lebanon area, and Republicans are always up for a war. But, I'm afraid they will get more than they bargained for.
