HOMS – On December 23, the Syrian government used chemical weapons against its opponents in Homs, sources in western intelligence services told Le Monde.

Throughout 2012, Western countries had warned Syria that if it crossed this “red line,” it would face an international military intervention. Now, these same countries are denying or minimizing the impact of the attack last month, “to avoid getting involved,” claim our sources.

The Syrian regime used “an incapacitating but non-lethal chemical weapon that remains unknown due to lack of samples,” according to our contacts. The substance was mounted upon “four rockets, which were fired.” The incident led to a “strong international reaction, particularly from Russia toward Damascus. We are now confident that the Syrian regime will not do this again.”

Since Dec. 23, Syrian activist networks have been relaying testimony from Homs inhabitants and doctors who are convinced that chemical weapons were used in the Al-Bayyada neighborhood, where a battle was raging between government forces and rebels. According to witnesses, the gas killed several people and poisoned dozens of others. Videos were posted on the Internet showing people with severe nausea, breathing problems, vomiting or choking. The problem with this information is that it can’t be verified and the fact that it comes from anti-Assad sources leaves room for interpretation.

In Paris, the spokesperson for the French foreign ministry, Philippe Lalliot answered our questions by saying “We checked the information closely, and especially the videos that were circulating. We cannot confirm the use of combat gases or lethal chemicals.” No clear denial, more like the expression of cautious reserve.

In Washington, on Jan. 16, the U.S. State Department spokesperson Victoria Nuland, gave the same response as her French counterpart: “We looked into the allegations that were made and the information that we had received and we found no credible evidence to corroborate or to confirm that chemical weapons were used.” Nuland was reacting to an article published the day before in the online edition of Foreign Policy magazine. It revealed the content of a diplomatic cable sent a week earlier by the American consul general in Istanbul, Scott Frederic Kilner.

In this document, Kilner, who was tasked by the State Department to investigate the attack, concluded that Damascus probably used Agent 15, an incapacitating nerve gas. Nuland did not deny the authenticity of the document, but played down the report. (On Tuesday, Foreign Policy posted a follow-up story on the matter)

Vast chemical arsenal

On Aug. 20, President Barack Obama declared that the use or loss of control over chemical weapons in Syria would be a “red line” and that there would be “enormous consequences.” On Aug. 23, British Prime Minister David Cameron stated that he shared the same view. On the Aug. 27, French President François Hollande added that the use of chemical weapons in Syria would mean a “legitimate direct intervention.”

The nature of Obama’s “consequences” was never defined, though. The distinction between lethal and non-lethal chemical weapons was never specified either. The Pentagon reckoned that 75,000 troups would be needed to secure Syrian chemical stocks.

The chemical arsenal in Syria has been described as the biggest in the Middle East, with stocks of mustard and sarin gas and the powerful VX nerve agent. Experts disagree on the presence of “Kolokol-1,” an incapacitating agent used by the Russian Special Forces during the hostage crisis in the Dubrovka theatre in October 2002 in Moscow.

In December 2012, the Obama administration raised alarm bells regarding possible signs of imminent use of chemical weapons in Syria (assembly of launching weapons). It had received information from Israeli authorities, who had already threatened to declare war if there was proof of chemical weapons transfers to extremist groups such as Hezbollah.

On Dec. 11^,, U.S. Secretary of Defense Leon E. Panetta told the press that relevant intelligence had “really kind of leveled off.” The reason, according to a recent New York Times article, was “a remarkable show of international cooperation,” that included Russia and Iraq, to avert a crisis. Every time there was an alert regarding chemical weapons, Russia claimed to be able to guarantee Damascus’ control of its stocks, with a standing threat to withdraw its support.

According to our sources in Western intelligence services, Syrian chemical weapons stocks were moved early December to a more secure storage location. Mark Fitzpatrick from the International Institute for Strategic Studies in London, said that the Assad regime, “on the edge of overthrow,” has been escalating, to the point where it fired Scud missiles on its own people. This expert hypothesizes that Assad might have thought that using “a non-lethal chemical weapon would be more “acceptable” to Westerners than a lethal one.

Another hypothesis can be drawn. The U.S.-Russian pressure on Damascus to stop using chemical weapons was a polite warning – the Superpowers will remain silent as long as Syria never uses its chemical arsenal again.