"We cannot determine all this. On some level, we’re assuming the reaction from Russia and Iraq and Syria will be zero: We’ll carry out this attacks, and there’ll be no response. This is a bit of a sensitive subject, but the administration has been honest that they have no smoking gun that the attack was ordered by Assad. The evidence of his involvement is circumstantial. We’re two years into a civil war that he’s winning. The Russians and Iranians have told him not to use chemical weapons. Hezbollah has told him not to use chemical weapons because their fighters are at risk. So he’s winning, there’s scant and circumstantial evidence that he ordered the attack. Why are we gaming out his incentives when we don’t know he ordered it?"
Says Alan Grayson, a Democratic congressman from Florida, in an interview with Ezra Klein (who's been doing some excellent interviews lately).