War is the great clarifier. The Russian move to quash both ISIS and the US-backed jihadist movement aimed at overthrowing Syrian strongman Bashar al-Assad has defined the lines of demarcation between the candidates for US President in both parties, and shown us what they are made of.

The issue at hand: should the US impose a "no-fly" zone in Syria, or parts of it, in order to stop the Russians from spoiling our little party?

On the one side, we have the President of the United States, who – foiled by popular opinion when he last tried to massively intervene in Syria's civil war – has apparently learned his lesson. He opposes a no-fly zone, at least for the moment. The Russian attempt to "prop up" Assad" is "just going to get them stuck in a quagmire," he said at a news conference, "and it won't work, and they will be there for a while if they don't take a different course." He went on to describe "half-baked" ideas about what to do in response to the Russian move, later claiming that he wasn't talking about Hillary Clinton's support for a no-fly zone – although it's hard to take him at his word on that. Clinton "is not half-baked in terms of her approach to these problems," he said, but "there's a difference between running for president and being president. And the decisions that are being made and the discussions that I'm having with the Joint Chiefs become much more specific and require, I think, a different kind of judgment. If and when she's president, then she'll make those judgments."