Since this story was published, there have been allegations of a major new chemical attack in East Ghouta, not far from Damascus. Hundreds of people are dead, according to the Syrian opposition. If the reports are even remotely accurate, this would be the biggest chemical weapons strike in decades. A preliminary examination of the footage by American intelligence officials and outside experts leads them to believe that chemical weapons were involved in the attack. But piecing together exactly what happened in Ghouta won't be easy; the Assad regime has taken deliberate steps to hide its chemical tracks, as the story below shows.
All of the major players in Syria -- and all of their major backers -- now agree that chemical weapons have been used during the civil war there. But the mysteries surrounding a string of alleged nerve gas assaults over the spring have, in some ways, only grown thicker. The motivations and tactics behind the unconventional strikes continue to puzzle U.S. intelligence analysts. And the arrival in Damascus of United Nations weapons inspectors holds little promise of solving the riddles.
Independent tests of environmental samples by both Russian and American spy services indicate that the deadly nerve agent sarin was used during a March 19 battle in Khan al-Assal, for example. Beyond that basic fact, there's little agreement. The Russians blame the Syrian rebels for launching that unconventional strike on the Aleppo suburb, while the Americans say it was a case of chemical friendly fire.
U.S. intelligence officials tell Foreign Policy that they're continuing to investigate claims of new chemical weapon attacks in Syria, including an alleged strike earlier this month in the town of Adra that left men foaming at the mouth and dogs twitching in the street. They're continuing to see supplies shuffled around some of Syria's biggest chemical weapons arsenals, such as the notorious Khan Abu Shamat depot.
But the number of reports of unconventional attacks has dropped sharply since early June, these same officials say. That's right around the time when forces loyal to dictator Bashar al-Assad took over the strategic town of Qusair and gained the upper hand in Syria's horrific civil war. The decline provides to American spy services another indication that it was Assad's forces who launched the chemical attacks; there's little need to gas people when you're winning.
There was a time when such determinations appeared to hold geopolitical significance. The Obama administration repeatedly called the use of chemical weapons a "red line." But that line has now been crossed repeatedly, with little consequence. And that's led U.S. intelligence officials to confront another question: How massive would the chemical strike have to be in order to prompt America and its allies to intervene in Syria in a major way?
"As long as they keep body count at a certain level, we won't do anything," an American intelligence official admits.
The U.N. inspection team arrived in Damascus on Sunday to test claims by Syria, Britain, France, and the United States that chemical weapons have been used in the country's two and a half year-long civil war. Ake Sellstrom, a Swedish scientist who is leading the U.N. mission, plans to spend at least 14 days in the country and to visit at least three sites where chemical agents have allegedly been used.
The team's arrival will mark the culmination of nearly five months of often-acrimonious negotiations over the U.N team's terms of access. It comes just weeks after Sellstrom and the U.N.'s undersecretary general for disarmament, Angela Kane, struck an agreement with top officials in Damascus on the terms of the inspections.
In advance of the visit, the United Nations has sought to dampen expectations that the team will blame one side or the other for using chemical agents. The mission's mandate, U.N. officials have repeatedly insisted, is simply to determine whether chemical weapons have been used, not to establish who ordered the attacks.
Rumors of chemical weapons use have been making the rounds since late last December, when reports surfaced indicating that chemical agent may have been used in a government offensive in Homs. But the accusations began to grow more numerous and more believable in March. It was Syria that first asked the United Nations Secretary-General Ban Ki-moon to conduct an investigation into the alleged use of chemical weapons on March 19 in Khan al-Assal, near Aleppo.
Syria's U.N. ambassador, Bashar al-Jaafari, alleged that Syrian rebels had attacked Syrian authorities with chemical weapons. He said the government has compiled medical reports, blood samples, and victim testimony supporting its claim, and invited the U.N. to send a team to Syria to evaluate the evidence. British and French officials believe that Syrian authorities may have indeed been exposed to chemical agent, but that they were the victims of a "friendly fire" attack conducted by Syrian forces.
But Syria balked after Ban agreed to a request by Britain and France to expand the investigation to sites where Syrian rebels claimed the government had used chemical weapons. Today, the U.N. has received a total of 13 allegations of chemical weapons use, mostly claims by the rebels that the Syrian government used chemical weapons.
Back in April, Ban said that a credible investigation would require the inspection team be granted "unfettered" access to all sites where chemical weapons have allegedly been used. But Security Council diplomats say that the U.N. has since backed down. Sellstrom believes that most of the cases of alleged chemical weapons use are too thin, or the evidence too old, to merit full-fledged investigations. He has honed in on three cases where, he believes, the trail is fresher and the evidence stronger. The U.N. has acknowledged that it will investigate the March 19 incident near Aleppo, but it has not revealed the location of the two other sites.
Syrian opposition leaders have expressed concern about the limited scope of the investigation. On Aug. 1, the Syrian National Coalition wrote Ban, saying the opposition "stand ready to cooperate fully with representatives of the mission and welcome UN investigators into all territories under its control." But the group remains concerned that the United Nations may be walking into a propaganda trap. "If the scope of the mission is restricted to only three sites, the coalition is worried that an important opportunity will be missed to establish authoritatively the extent to which chemical weapons have been used," said Najib Ghadbian, the coalition's U.N. representative. "There is an urgent need for the UN to conduct a comprehensive investigation into all credible allegations of chemical weapons uses."
Ghadbian urged the U.N. to visit all of the sites where such weapons may have been used, including during the latest incidents in Adra and Douma. That's not likely to happen. Not only are these highly contentious war zones. But the chemical claims are often questionable. Take the attack in Adra earlier this month. A YouTube video shows victims complaining of a sulfur smell; the Assad regime's chemical weapon of choice, sarin, is generally odorless. The clip also shows victims foaming at the mouth; sarin doesn't ordinarily produce such an effect.
U.S. analysts speculate that some of these atypical effects may be the result of Assad's military using an atypical mix of chemical arms, so-called "riot control agents," and conventional munitions on the battlefield. In December, one former chemist for the Syrian regime told Al Jazeera that this blending of weapons was done, in part, to create a confusing blend of symptoms -- and mask their source.
Traditionally, militaries launch chemical attacks separately from ordinary ones. Not so in Syria. In a single bombing run near Aleppo last May, for instance, U.S. intelligence believes that a single Syrian warplane dropped bombs loaded with tear gas, sarin, and conventional explosives.
"When we first started hearing about this, we didn't understand. Why one sarin bomb in the middle of a major bombardment?" asks one U.S. intelligence official. Perhaps it's a way to cover up the use of chemical weapons, as the chemist suggested. Perhaps it was to force potential enemies out into the open. Perhaps it's a way to further terrorize the targets of the bombing runs. "We think it's strange, but whatever the Syrians have been doing, it's been very effective," the official adds. After all, the government appears, for now, to be winning the war.
Contributing to confusion is the long-standing suspicion that Assad's forces are brewing up their unconventional weapons in unconventional ways. One of sarin's two main precursors is isopropanol -- rubbing alcohol, basically. But the material used for chemical attacks can't be purchased in any drug store. While the commercial stuff typically is 70 percent water, the weapons-grade isopropanol is highly concentrated, with less than 1 percent water. That makes it extremely hard to obtain. Some outside observers believe the Syrians are using less isopropanol than usual in their sarin in order to preserve their precious stockpile of the precursor. (It would also produce milder-than-normal effects in a victim.) If the dilution theory is true, it could be an indication that Assad intends to hold on to his chemical arsenal for a long, long time -- and unleash it only when his rule is once again under threat.