As to the new concern about Iran and Russia is they know they are beating a Dead Horse on Syria as the American People have seen through the silliness of their arguments for the proposed Attacks on Syria and they have to find another bogus excuse to continue their campaign to save Obama's Face.
I don't think the reason is bogus - far from it. The threat from both was there for all to see from the outset. The thing is is that its hard for the man-in-the-street to make this connection, let alone comprehend the implications of action or inaction. I think you're right though that the Administration is getting a little desperate.
I wonder where we'd be now if Obama hadn't made that un-guarded comment...