Via David Shor and Aaron Zelin, who was quick this morning in remembering that today’s apparent chemical massacre outside Damascus falls a year to the day from Obama issuing his empty “red line” threat. Is that why Assad did it, to show the world that he’s still alive, kicking, and defying the United States a year after O talked fake-tough about him? The “red line” comment backfired long ago by forcing Obama to take action, however feeble, in the name of protecting American credibility. Who knows if he would have decided to arm the Syrian rebels if he hadn’t boxed himself in rhetorically? (Which, actually, might explain why the rebels haven’t received those arms yet.) If this new chemical attack was a reaction to his comments last year, though, that’s a backfire of historic dimensions.

Ed was skeptical earlier, for good reasons, that the attack really was chemical, but U.S. intelligence appears to think it’s legit. It might not be sarin, but it’s something:

“No doubt it’s a chemical release of some variety — and a military release of some variety,” said Gwyn Winfield, the editor of CRBNe World, the trade journal of the unconventional weapons community…

“Because of the intensity of the gas, a majority of victims were found with heavy respiratory secretions, myosis, and muscular spasms,” Layman said, after speaking with the director of the Douma city medical office, a man who goes by the nom de guerre Khaled ad-Doumi. “Atropine, the chemical used to curb the effects of these chemical attacks, has had only limited effects.”

However, Winfield, after examining video and photo evidence of the attack, doubted that pure sarin was involved. “There doesn’t seem to be quite enough mucus or saliva for a pure organophosphate,” he said, referring to the class of chemical to which nerve gases belong. “No doubt it’s a chemical release of some variety … But it’s too weak for a pure sarin release.”

“If indeed 600 [or more] people were killed, the attack would have had to involve a large amount of chemical agent,” Elleman said. “Which means it would have had to be delivered in a very deliberate fashion, and that would be a strong indicator that it was deliberate use or not accidental use, or just spraying munitions, which may be what happened in the past – we don’t know.”

The UN’s holding an emergency session this afternoon, but nothing can happen at the Security Council if, as expected, Russia vetoes whatever’s proposed. Is that likely to happen? You tell me.

The Times has an amazing line-up of video from the aftermath of the attack. Two questions to mull while we wait for the UNSC to do nothing. One: Ed noted this morning that it seems unlikely Assad would stage a big chemical massacre at a moment when UN inspectors are inside the country, but if Zelin’s theory that Assad did this as a middle finger to Obama and the world is correct, the presence of inspectors only makes the defiance sweeter for him, no? Note that the inspectors aren’t free to investigate the new attack either — their movements are restricted to the locations of previous alleged chemical attacks — so it’s not like they’re a threat to find the smoking gun of what just happened. Two: Did the timing here have anything to do with what’s happening in Egypt? Now that the Muslim Brotherhood is under Sisi’s thumb, with the west unwilling to do much to intervene, Assad might have decided to “celebrate” the world’s Strange New Respect for dictatorship in the name of keeping Islamists in line by showing how far he’s willing to go to do that. Even if his victims weren’t Islamist.