Over the weekend, the United Kingdom joined the United States in warning publicly about Syria’s intentions regarding its chemical weapons. Foreign Secretary William Hague told reporters that the U.K. was concerned both about recent evidence that the regime could use chemical weapons against Syrian rebels or citizens, and about the possibility that these weapons could fall “into the hands of other people.” This comes on the heels of Leon Panetta’s statement last week that President Obama “has made very clear that there will be consequences if the Assad regime makes a terrible mistake by using these chemical weapons on their own people.”

Virtually everyone agrees that a decision by Assad to use chemical weapons against rebels or civilians – or a failure to maintain Syrian government control over those weapons – would produce frightening outcomes. But what, precisely, would the U.S. Government’s justification be for using force in Syria to prevent these outcomes? Somewhat ironically, the U.S. may have a stronger legal case to act if Syria transfers (or loses control of) its chemical weapons stock than if Syria uses them against individuals within Syria.

Ashley S. Deeks, Syria, Chemical Weapons, and Possible U.S. Military Action, Lawfare (December 10, 2012).