WASHINGTON -- An unsubstantiated charge by a Syrian government-controlled media outlet that rebels deployed chemical weapons in their battle against the government of President Bashar Assad prompted American lawmakers on Tuesday to sound the alarm about weapons of mass destruction and urgently call for a U.S. military response.
The latest chemical weapons claim emerged Tuesday on a Syrian state-run news channel, which broadcast video of people it claimed had been victims of a rebel attack in the contested city of Aleppo. In response, rebel forces said a chemical attack had in fact been launched by the government, and released their own videos showing victims apparently choking from fumes. Both sides put the death toll at about 25.
Reports of chemical weapons use in Syria are not unprecedented, but none has been confirmed by international authorities. President Barack Obama has described the use of chemical weapons by Assad as a "red line," and pledged to take military action if it occurs.
At the White House Tuesday, spokesman Jay Carney said U.S. officials were "looking carefully at the information." He added that the administration remained "deeply skeptical" of at least the Syrian government's version of the story.
But the caution in one part of Washington did little to influence lawmakers across town, who -- on the 10th anniversary of the U.S. invasion of Iraq -- rose to demand swift and decisive military action if the chemical attack reports prove true.
Two top foreign policy lawmakers, Sen. Lindsey Graham (R-S.C.) and Sen. Carl Levin (D-Mich.), separately called for the White House to step up military action in Syria, with Graham arguing that Obama should consider having American troops "get on the ground" to help secure chemical weapons sites.
Later in the evening, the heads of the Senate and House Intelligence Committees, Sen. Dianne Feinstein (D-Calif.) and Rep. Mike Rogers (R-Mich.), joined forces on CNN to say that they believed chemical weapons had likely been used, without offering evidence. They said the White House should consider military action.
"If in fact we prove beyond a shadow of a doubt they have used these chemical weapons ... I think we are morally obligated to do something about their ability to deliver these weapons," said Rogers. "And if that was a very limited military strike to do that -- again, I think we're morally obligated to do that."
Administration officials have long said they have drafted plans for military action against Syria's chemical weapons stores, if need be. But officials and defense experts have also repeatedly cautioned that none of the plans are likely to meet Rogers' definition of "limited military strikes."
In fact, experts said that bombing suspected chemical weapons sites -- many believed to be heavily fortified underground bunkers -- would be unlikely to disable the program, and may risk dispersing chemicals through the air.
A more realistic scenario for securing the weapons would require a large-scale air campaign and tens of thousands of ground troops, according to the Pentagon. A November Pentagon study concluded that properly securing Syria's chemical weapons depots would require at least 75,000 troops.
Then there's the question of whether a strike would reliably destroy all chemical weapons, or if remainders would be more likely to be used by the government or fall into the hands of rogue forces. Administration officials have told reporters that while they can monitor chemical weapons, they "don't have perfect visibility to all the chemical weapons sites."
"This would not be a simple operation," said a recent report by the International Institute for Strategic Studies. "Syria has strong air defences, and even if everything on the target list were hit, there is a serious risk of releasing agents into the atmosphere. Some munitions could even survive the strikes and be looted from abandoned bases, while any secret storage facilities could be left intact."
Meanwhile, the evidence that Tuesday's attack used chemical weapons remained sketchy.
A Reuters photographer on the scene of the attack in Aleppo told the news agency that women and children reported a strong smell of chlorine in the air. A British expert quoted by Voice of America said the smell of chlorine is not uncommon in a conventional weapons attack and was far from conclusive.
Speaking to Al Jazeera, Ziad Haddad, a medic based in Aleppo who treated some civilians after the attack, said he believed they had likely been exposed to a pesticide rather than a chemical weapon like Sarin or VX gas.
"Victims spoke of pungent smell. Chemical weapons are usually odorless," Haddad said. “Moreover, the number of deaths is small compared to those who would have died had chemical weapons been used."
In a separate study published Tuesday, the Rand Corp., a military policy think tank, suggested that the Assad regime still faces significant disincentives against using chemical weapons. The prospect of American intervention, the report said, may be enough to prevent Assad from deploying them. The use of chemical weapons might also push Russia and China to withdraw their diplomatic protection.