Syria's chemical-weapons program is considerably larger than Libya's, which would presumably make monitoring it more of a challenge.
"This is a full-blown chemical-weapons program, not the remnants" of one, as in Libya, Spector said. "You have large inventories ... there are a lot of people milling around the sites," presumably guarding them and managing day-to-day operations.
Syria's chemical-weapons program is understood to be comprised of four production facilities, at al-Safira, Hama, Homs, and Latakia, along with two munitions storage sites at Khan Abu Shamat and Furqlus. Additionally, there is a chemical-weapons research laboratory near Damascus, according to Michelle Dover of the James Martin Center.
"You're also looking at a program that is almost completely self-sufficient from the research and production through the storage and weaponization," said Dover, citing open-source information dating back to the 1980s.
The Assad regime is thought to possess between 100 and 200 Scud missiles carrying warheads loaded with sarin nerve agent. The government is also believed to have several hundred tons of sarin agent and mustard gas stockpiled that could be used in air-dropped bombs and artillery shells, according to information compiled by the James Martin Center.
"We do not have any information that suggests there have been changes to the security of Syria's chemical-weapons stockpile," a State Department official said in an e-mail to GSN. "Syria is a country of significant proliferation concern, so we monitor its chemical-weapons activities very closely. We will continue to work closely with like-minded countries to limit proliferation to Syria's chemical-weapons program. We believe Syria's chemical-weapons stockpile, composed of nerve agents and mustard gas, remains under Syrian government control."
Damascus is a well-known backer of Hamas and Palestinian Islamic Jihad, which both base their headquarters in the Syrian capital. Syria is also a supporter of Hezbollah and last year was accused by Israel of providing Scud ballistic missiles to the Lebanese militant group.
Noting reporting on contingency plans prepared by the Pentagon for military operations to prevent militants from obtaining Pakistani nuclear weapons, Spector said it was reasonable to extrapolate that preparations have also been made to respond to crisis situations involving Syria's chemical arms.
Such events might include the Assad regime preparing its chemical arsenal for an air attack on protesters and army defectors or the weakening of security around the chemical sites. The details of presumed action plans are closely held.
"It would seem illogical to think that Pentagon has not brainstormed contingency plans," Spector said.
Spector said he believes the United States has "definitely" issued backdoor diplomatic threats to Damascus of serious consequences should Assad order chemical-weapon attacks on opposition activists. "I'm sure that message has been conveyed."
Although Washington is concerned about the potential chemical-weapons threat, it is not the Obama administration's primary focus in dealing with Syria, according to the issue expert. "I think they have still-more-urgent items that are constantly on top of the agenda," such as persuading the Arab League to pass sanctions against the regime and pushing for Assad to step down, he said.
A key factor in U.S. contingency thinking is thought to be what actions Israel could take unilaterally if it believes that a chemical-weapons attack or proliferation is imminent, Spector said.
Israel in June 2007 mounted a sneak aerial attack on a Syrian site at Dair Alzour that it suspected of housing an unfinished atomic reactor with military applications.
A crucial element of any potential Israeli calculus on striking against Syria's chemical assets would be identifying the exact location of the weapons, Spector said.
"You have a lot of sites, and not all of them may be known, and you really have to do a lot of work;, you really have to get everything," Spector said.
Also likely weighing on Israeli and U.S. thinking is whether a strike on Syria's chemical arsenal could backfire by pushing opposition forces to rally around Damascus in response to a foreign attack, Spector said. "You don't want to create an environment where the country rallies around the government because they face an external attack."
The Israeli Embassy in Washington did not respond to requests for comment by press time.
This article was originally published in Global Security Newswire, produced independently by National Journal Group under contract with the Nuclear Threat Initiative. NTI is a nonprofit, nonpartisan group working to reduce global threats from nuclear, biological, and chemical weapons.