The regime has readied part of its arsenal:
Engineers working for the Assad regime in Syria have begun combining the two chemical precursors needed to weaponize sarin gas, an American official with knowledge of the situation tells Danger Room. International observers are now more worried than they’ve even been that the Damascus government could use its nerve agent stockpile to slaughter its own people.
[He] faces an impossible dilemma. From his point of view, the only rationale for using these weapons would be if his downfall would otherwise be absolutely inevitable. On the other hand, if he did choose to gas his enemies, that would be certain to trigger a US-led intervention that would seal his fate anyway. So rationality dictates that he should not use these weapons under any circumstances. But even if Assad is a still a rational actor, is he fully in control? And does there come a point in the inexorable collapse of a dictatorship when rationality itself goes out of the window and the bunker syndrome takes over?
Former UN advisor George Lopez fears the worst:
[F]or those who believe the rebel control of regions near the Turkish border should lend itself to international agencies providing direct humanitarian relief as winter comes to desperate refugees – recall that in their last disclaimer about chemical weapons, the regime said they would only use them if the nation faced foreign intervention. So Assad’s sick logic would excuse and explain his use of chemical weapons against rebel forces entering Damascus or along the Turkish border almost any time now. In short, we should be worried – very, very worried.
Goldblog reports that Israel has tried to get Jordan's permission to bomb Syria's chemical weapons:
Of course, Israel can attack these sites without Jordanian approval (in 2007, the Israeli Air Force destroyed a Syrian nuclear reactor), but one official told me that the Israelis are concerned about the possible repercussions of such an attack on Jordan. "A number of sites are not far from the border," he said, further explaining: "The Jordanians have to be very careful about provoking the regime and they assume the Syrians would suspect Jordanian complicity in an Israeli attack." Intelligence sources told me that Israeli drones are patrolling the skies over the Jordan-Syria border, and that both American and Israeli drones are keeping watch over suspected Syrian chemical weapons sites.
Aaron Stein says preemptive strikes may indeed happen, should any further preparation of the weapons occur:
[T]he U.S. and Israel are also using the media to tell Bashar that they will not wait for the use of chemical weapons, but will take action if intelligence indicates that their use is imminent. It is not hard to imagine a scenario where U.S. intelligence assets (drones, satellites, human) begin to witness the preparations for the launch of Syrian Scuds. If the threat is deemed credible, one can imagine a U.S. air strike on the missiles while they are being fueled and still on the ground.
(Image from the Deaths of Syria project)