The latest estimates say that the Assad regime has hundreds of tons of mustard gas, a blister agent, and large stockpiles of sarin and possibly VX, both of which are nerve agents -- all of which can be launched by Scud missiles, artillery, or aircraft, according to Charles Blair, a specialist in chemical and biological weapons at the Federation of American Scientists. "I've heard that Syria has 100 to 200 missiles with nerve agents loaded and ready to go, but that seems extreme," said Blair, noting that the nerve agents are usually stored separately from the weapons and that exact estimates about the size of the regime's stockpile are almost impossible to come by.
Although the U.S. government has released only vague estimates as to the size of Syria's chemical and biological weapons stockpile, Dempsey told lawmakers in March that the arsenal was "100 times the magnitude we experienced in Libya." Libya acceded to the international Chemical Weapons Convention in 2004 and had largely destroyed its useful stockpile of such weapons by the time Qaddafi's regime fell in 2011, according to Blair.
"Outside of the people who actually made and have guarded this stuff, I doubt that anyone could answer your question with any amount of accuracy," said Amy Smithson, a senior fellow with the James Martin Center for Nonproliferation Studies.
Although Assad's stockpiles are thought to be considerable, Blair believes the dictator is unlikely to deploy them because using chemical weapons against civilians would only "build support for international intervention."
"I think they are moving them to protect the weapons from a
preemptive attack by Israel," Blair said, or because information about the locations
of the weapons -- which he called the "top gems" of the Syrian military -- have
been compromised by high-level defectors from the Syrian army.
Aram Nerguizian, an expert on the Syrian military with the Center for Strategic and International Studies, agreed, saying that Syria has so far restrained itself from using the most potent weapons in its arsenal, such as fixed-wing bombers and its larger multiple-launch rocket systems, against the rebels for fear of fueling international outrage, the way Qaddafi's government did in Libya. "You haven't had the utilization of mass airpower or mass artillery," such as guided rockets, he said. "If airpower is a red line, using chemical weapons would go well beyond any red line."
"I'm more concerned about a direct strike against the regime or other military actions," said Nerguizian. "Those are the kinds of things that would really make units [guarding the chemical weapons] abandon their posts and expose chemical or biological weapons and major SAM and other systems to acquisition by outlaw third parties. We often hear we need to intervene to secure those chemical weapons. The reality is, if we intervene, we're going to destabilize a lot of the safeguards" keeping those weapons safe.
Blair agreed, saying that it would likely take tens of thousands of people to guard Syria's chemical weapons should the regime crumble, saying, "any cohesive plan that secured all [chemical munitions] sites" would be difficult to implement.