A few days ago Secretary of State John Kerry said that the U.S. believes that chemical weapons were used last week in an attack near Damascus. Given that the United Nations inspectors have yet to release the results of their examination of the sites of the suspected chemical attacks it is fair to ask how Kerry knows that chemical weapons were used.
The footage from the sites of the attacks do strongly suggest that chemical weapons were used on civilians. Footage of the aftermath of the attacks does not show those who died having any obvious wounds that would be expected had they been killed by conventional weapons, and many of those filmed seemed to be suffering from the effects of a sarin gas attack. Doctors Without Borders says that hundreds of the patients they were treating with "neurotoxic symptoms" have died. However, as strong as the anecdotal evidence is, it does not definitively confirm exactly what sort of weapons were used, or who used them.
Foreign Policy's blog "The Cable" has an article up explaining why U.S. intelligence analysts are sure that chemical weapons were used near Damascus last week by Assad's forces.
From Foreign Policy:
Last Wednesday, in the hours after a horrific chemical attack east of Damascus, an official at the Syrian Ministry of Defense exchanged panicked phone calls with a leader of a chemical weapons unit, demanding answers for a nerve agent strike that killed more than 1,000 people. Those conversations were overheard by U.S. intelligence services, The Cable has learned. And that is the major reason why American officials now say they're certain that the attacks were the work of the Bashar al-Assad regime—and why the U.S. military is likely to attack that regime in a matter of days.
But the intercept raises questions about culpability for the chemical massacre, even as it answers others: Was the attack on Aug. 21 the work of a Syrian officer overstepping his bounds? Or was the strike explicitly directed by senior members of the Assad regime? "It's unclear where control lies," one U.S. intelligence official told The Cable. "Is there just some sort of general blessing to use these things? Or are there explicit orders for each attack?"
The article goes on to point out that the U.S. does not have what would be traditionally considered hard evidence of the use of chemical weapons (tissue and environmental samples), and that White House Press Secretary Jay Carney considers the work of the U.N. inspectors in Damascus, who are working on gathering such evidence, "redundant" given what the Obama administration already reportedly knows.
From Foreign Policy:
However, U.S. spy services still have not acquired the evidence traditionally considered to be the gold standard in chemical weapons cases: soil, blood, and other environmental samples that test positive for reactions with nerve agent. That's the kind of proof that America and its allies processed from earlier, small-scale attacks that the White House described in equivocal tones, and declined to muster a military response to in retaliation.
There is an ongoing debate within the Obama administration about whether to strike Assad immediately—or whether to allow United Nations inspectors to try and collect that proof before the bombing begins. On Tuesday, White House Press Secretary Jay Carney called the work of that team "redundant … because it is clearly established already that chemical weapons have been used on a significant scale."
Even if, as is looking increasingly likely, the Assad regime did use chemical weapons in Syria it is unclear why the use of such weapons should be considered a "red line."