Did Russia know Syria still had sarin gas?

Regarding the 59 missile strike on the airfield in Syria where the chemical weapon attack originated:   We've been concentrating so much on Trump's decision and what it means vis a vis our foreign policy (or lack thereof) that we've paid little attention to Russia's role.

Our intelligence has suggested, though not yet concluded, that the Russians knew in advance about Syria's plan to use gas on civilians.   S. V. Date, writing for the Huffington Post, asks how could they not have known?   Russian troops had been at this same base, using their runways, mingling with Syrian pilots who use Russian-made planes.

Russia has countered with the suggestion that Syrian planes could have inadvertently bombed an installation where rebel forces stored chemical weapons.  Russia has called for a thorough investigation to determine who is responsible.  This is most likely a sign that they have covered up any evidence that chemicals were ever at the airbase.

Date's report quotes a U.S. official saying that there is simply too much corroborating evidence.  “It’s just too massive for any intelligence organization to fabricate in that short a time. . . .  I think it’s clear the Russians are trying to cover up what happened there.”

Ever since 2013, when Russia assumed the responsibility for receiving and destroying Assad's cache of chemical weapons, in a deal brokered by Obama, “The Syrian regime and its primary backer, Russia, have sought to confuse the world community about who is responsible for using chemical weapons against the Syrian people in this and earlier attacks,” according to an unclassified U.S. memo.

Why another chemical attack now?  Again, U.S. officials at a briefing suggested that Assad is trying to punish civilians in a territory where rebel forces have been making progress and moving closer to government-held population centers and military bases.  Others have suggested it was more a test to see how Trump would respond, especially since, days before, Trump had stated that it was up to the Syrian people to decide about Assad's regime.

Sen. Chris Murphy (D-CT) addressed the "why now?" question in light of his belief that Assad is in a stronger position in Syria than any time since 2013.   He wrote in an op-ed:   "The answer likely lies in the green light that the Trump administration gave Assad just a few days before the chemical weapons attack was launched. . . . "

If Assad's future, as both Trump and Secretary of State Rex Tillerson had said just prior to this, is up to the Syrian people -- which Murphy points out is "a regular Russian talking point" -- then Assad assumed he was "free to act without repercussions," a point also made by Sen. Mark Rubio (R-FL).

There is also the concern about how Russia has carried out its agreement to destroy the chemicals (did it allow Syria to keep some?) and to make sure that they did not acquire new chemicals.  Assuming that it is shown beyond reasonable doubt that it was Syrian forces that used them, Russia has some explaining to do.

One other thing that hasn't received much commentary:   On the surface anyway, Trump's response to this suggests that Putin does not have as much control over Trump as we had feared -- unless, of course, we're seeing play out a covert agreement between Trump and Putin to have a sham confrontation to throw us off the trail.

Frankly, Trump is so bad at subterfuge that I think that is unlikely.   Political theater -- creating a lot of obfuscating smoke -- I grant, he does well.   But actual, closely-observed, spy-worthy deception, he usually flunks.

Ralph