Could Damascus be preparing chemical weapons?

The US says it has detected activity which could suggest that Bashar al Assad's regime is developing chemical weapons. 19 months into the conflict between Damascus and the rebel uprising, both sides have reached stalemate; the rebels appear to be holding their positions, even though they claim not to have received help from outside Syria. US Secretary of State Hillary Clinton has said using chemical weapons against their own people would be a "red line" that would force Washington to react.