The big question to which foreign policy commentators are starting to turn their attention is this: how much exactly is at stake in the US presidential election?

Experts tend to do badly at this question. In the 2000 race between Al Gore and George W. Bush, the received wisdom was that the foreign policy differences between the candidates were minimal. It was presumed that a President Gore would continue the centrist international approach of the Clinton administration, in which he had been such an important player. Meanwhile, the Republican team hosed down expectations that a President Bush would pursue a more muscular strategy. All this led Robert Kagan to publish an op-ed in The Washington Post titled “Vive what difference?”, in which he asked glumly: “When it comes to international affairs, is there really any difference between Bush and Gore?”