The attacks of March 19, August 24 and August 25, 2013 upon Syrian government soldiers indicate that the rebels were in possession of sarin both before and immediately after the chemical weapon attack at Ghouta of August 21, 2013. It would have been virtually impossible for the rebels to acquire chemical weapons so quickly in late August had they not already previously been in possession of chemical weapons.
According to Seymour Hersh, December 19 ( published in The London Review of Books),
“already by late May, the senior (US) intelligence consultant told me, the CIA had briefed the Obama administration on al-Nusra and its work with sarin, and had sent alarming reports that another Sunni fundamentalist group active in Syria, al-Qaida in Iraq (AQI), also understood the science of producing sarin. At the time, al-Nusra was operating in areas close to Damascus, including Eastern Ghouta. An intelligence document issued in mid-summer dealt extensively with Ziyaad Tarriq Ahmed, a chemical weapons expert formerly of the Iraqi military, who was said to have moved into Syria and to be operating in Eastern Ghouta. The consultant told me that Tariq had been identified ‘as an al-Nusra guy with a track record of making mustard gas in Iraq and someone who is implicated in making and using sarin.’ He is regarded as a high-profile target by the American
military.”
This would support the Russian Ambassador’s claim, following the Security Council consultations of December 17, 2013 that: “Why would the Syrian government use chemical weapons on August 21? To cross the red line drawn by Washington and invite a missile strike upon itself? Why would the opposition use chemical weapons? Exactly because of the red line. To provoke foreign military intervention in the Syrian conflict…The Russian team’s analysis concluded that ‘home-made’ sarin was used near Aleppo on March 19. It stated that the Sarin was likely delivered by a crudely made missile. The team also named the particular opposition group most likely behind the attack. At the time, the Syrian government immediately requested an international investigation of the March 19 incident, but then the United Kingdom and France all of a sudden recalled a Homs case, that had not bothered them for 3 preceding months, while the US started insisting on the need to investigate ‘all incidents.’ Why did those who accused the Syrian government of this act do their utmost to derail or at least delay such investigation?” The dragging UN probe was interfered with by the tragic events in Ghouta on August 21. “As our experts concluded, sarin used on August 21 was of approximately the same type as the one used on March 19, though of a slightly better quality. It means that over a few months, opposition chemists somewhat improved the quality of their product.”
According to Seymour Hersh,
“Theodore Postol, a professor of technology and national security at MIT, reviewed the UN photos with a group of his colleagues and concluded that the large calibre rocket was an improvised munition that was very likely manufactured locally. He told me that it was ‘something you could produce in a modestly-capable machine shop.’ The rocket in the photos, he added, fails to match the specifications of a similar but smaller rocket known to be in the Syrian arsenal.”