More 11D Chess From Putin: Russia Informed US It Would Sarin-Bomb Idlib 24 Hours in Advance

Assad doesn't always gas civilians, but when he does he apparently has Moscow tell the US when and where it is going to happen

Here is a safe assumption to make: If you're to be gas-bombing civilians you won't be telling your information war foes where and when it is going to happen. 

However, that is precisely what the US alleges Russia and Syria did.

US officially denies it, but American sources in the know confirm it. Russians had told the Pentagon that a Syrian bombing run against a Khan Sheikhoun warehouse was in the works 24 hours before it happened.

Why in the world would they do that if they were planning to sneak in a chemical weapons attack?

The great Gareth Porter (read his superb book on the manufactured Iran crisis) reports for Truthout

The US military allegedly knew in advance that the strike was coming: Russian military officers informed their American counterparts of the Syrian military's plan to strike the warehouse in Khan Sheikhoun city 24 hours before the planned airstrike, according to the former US official who spoke with Truthout. The official is in direct contact with a US military intelligence officer with access to information about the US-Russian communications.

What's more:

The military intelligence officer reported to his associate that the Russians provided the information about the strike to the Americans through the normal US-Russian Syria deconfliction telephone line, which was established after the Russian intervention in 2015 to prevent any accidental clash between the two powers. The officer said that Russia communicated to the US the fact that the Syrians believed that the warehouse held toxic chemicals. 

That information was considered so politically sensitive that after its initial dissemination, it was available only to a few officials, the US military intelligence officer told his associate.

It's from an anonymous source but if Porter is vouching for him it's solid.

So not only did Americans conclude the civilian massacre at Khan Sheikhoun was the result of an unlikely aerial chemical weapons bombing announced a full day in advance — they did so even though they had reason to suspect the target site held toxic chemical agents. 

Well why the heck not. If you're going to be a weapons supplier for the Syrian al-Qaeda, why not be their willing dupe as well.

For the record: The MIT professor Theodore Postol shows the US/Qaeda claim that poison gas at Khan Sheikhoun was delivered via aeroplane is just about impossible.