Syrian opposition forces said that up to 30 people died in attacks in March, and most of the photo evidence showed survivors exhibiting signs of what could be sarin exposure, such as foaming at the mouth and constricted pupils. In the much deadlier August attacks – some opposition sources claimed the death toll was as high as 1,300 – survivors showed the same telltale signs of possible sarin exposure.
Evidence of the use of sarin in Syria is coming in the form of photos, videos, soil samples, and blood samples – the latter being the most conclusive form of evidence, according to military experts. But the blood samples from the earlier attacks were provided by Syrian opposition forces, according to US officials speaking on the condition of anonymity – a fact that reduced the “degree of confidence” that US intelligence agencies had in them because they could have been tainted to provide a particular conclusion.
This is why the US and other countries, including Britain and France, pressed so hard for a UN chemical weapons investigation team to gain access to Syria. That team finally arrived in mid-August – just days before the most recent attacks and only after months of high-stakes diplomatic wrangling.
Assad was originally supportive of a UN team investigating one reported March 19 attack – but when UN Secretary General Ban Ki-moon called for the team to look into all reported incidents of chemical weapons use, Assad balked.
Siding with Assad, Russia said a broadened investigation risked turning into a repeat of the UN’s investigation of Saddam Hussein’s “weapons of mass destruction” – weapons that as it turned out did not exist, but which nevertheless served as the pretext for the US invasion.
