When President Obama first warned Syria’s leader, President Bashar al-Assad, that even making moves toward using chemical weapons would cross a “red line” that might force the United States to drop its reluctance to intervene in the country’s civil war, Mr. Obama took an expansive view of where he drew that boundary....
But in the past week, amid intelligence reports that some precursor chemicals have been mixed for possible use as weapons, Mr. Obama’s “red line” appears to have shifted. His warning against “moving” weapons has disappeared from his public pronouncements, as well as those of Secretary of State Hillary Rodham Clinton. The new warning is that if Mr. Assad makes use of those weapons, presumably against his own people or his neighbors, he will face unspecified consequences. -- New York Times
According to the Pentagon (and outside experts) efforts to neutralize Assad's chemical stockpile could entail upwards of 75,000 troops and days of airstrikes. And, as the Times piece notes, bombing chemical weapons depots could simply release the toxins into the air -- the very result everyone is trying to avoid. Many of those stockpiles are in urban areas and efforts to destroy them may also facilitate their uncontrolled spread if they're not entirely destroyed at the outset.
Moreover, and to put it bluntly, if tens of thousands of Syrians dying by mortar round and small arms fire hasn't moved the U.S. to intervene, it's not clear why Syrians dying by chemicals would be any different. The only reason I can see is a desire to enforce a norm against the use of WMD -- but is that reason enough to deepen U.S. involvement? The U.S. has an obvious interest in this norm, but so do all civilized states. (I'm personally on the fence. I can see the argument for attacks, not against Syrian chemical weapons depots perhaps but against regime assets -- Assad's house, military bases and airfields, etc. -- if Assad takes that fateful step.)