For 24 hours, I've been trying to work out why people have been so worried about Turkey downing a Russian plane. Or rather, I've been trying to work out why the worry people have expressed over it has surprised me. Then I realised: many people take it as a sign that there's a possibility of war.

But, well, of course there's going to be a war. Or war in general. There has been war for the last 15 years across a vast swathe of territory. But that's not what is meant. Of course there are going to be wars between advanced nations in the distant future, or tomorrow. Of course we are headed for war. Limited, strategic, surgical -- unless they get out of hand -- but war nevertheless.