Syria has some 75 sites where weapons are stored, but U.S. officials aren’t sure they have tracked down all the locations, and fear some stockpiles may have already been moved. Syria is believed to have several hundred ballistic surface-to-surface missiles capable of carrying chemical warheads, plus several tons of material stored in either large drums, or in artillery shells, which become deadly once fired.
‘‘In Syria, they have everything from mustard agent, Sarin nerve gas, and some variant of the nerve agent VX,’’ according to James Quinlivan, a Rand Corp. analyst who specializes in the elimination of weapons of mass destruction.
A primary argument against sending in U.S. ground troops is that whoever takes possession of the chemical weapons will be responsible for destroying them, as part of the 1997 Chemical Weapons Convention. Destroying Syria’s stockpiles could cost hundreds of millions of dollars, and take more than a decade, Quinlivan said.
Syria’s arsenal is a particular threat to the American allies, Turkey and Israel, and Obama singled out the threat posed by the unconventional weapons earlier this year as a potential cause for deeper U.S. involvement in Syria’s civil war. Up to now, the United States has opposed military intervention or providing arms support to Syria’s rebels for fear of further militarizing a conflict that activists say has killed more than 40,000 people since March 2011.
Activity has been detected at Syrian weapons sites before.
Defense Secretary Leon Panetta said in late September the intelligence suggested the Syrian government had moved some of its chemical weapons in order to protect them. He said the U.S. believed that the main sites remained secure.
Asked Monday if they were still considered secure, Pentagon press secretary George Little declined to comment about any intelligence related to the weapons.
Senior lawmakers were notified last week that U.S. intelligence agencies had detected activity related to Syria’s chemical and biological weapons, said a U.S. intelligence official, speaking on condition of anonymity to discuss the closed-door meetings. All congressional committees with an interest in Syria, from the intelligence to the armed services committees, are now being kept informed.
‘‘I can’t comment on these reports, but I have been very concerned for some time now about Syria’s stockpiles of chemical weapons and its stocks of advanced conventional weapons like shoulder-launched anti-aircraft missiles,’’ said House intelligence committee Chairman Mike Rogers, R-Mich.
‘‘We are not doing enough to prepare for the collapse of the Assad regime, and the dangerous vacuum it will create. Use of chemical weapons by the Assad regime would be an extremely serious escalation that would demand decisive action from the rest of the world,’’ he added.
The U.S. and Jordan share the same concern about Syria’s chemical and biological weapons — that they could fall into the wrong hands should the regime in Syria collapse and lose control of them.
Associated Press writers Bradley Klapper in Prague, Josef Federman in Jerusalem, Albert Aji in Damascus and Matthew Lee, Lolita C. Baldor and Julie Pace in Washington contributed to this report.