Grappling with European history, it can sometimes help to ponder it as a series of key moments. Strikingly, these were often military clashes where the outcome was finely balanced. How different, for example, might Europe be today if Gebhard Leberecht von Blücher had not arrived in time to buttress Wellington at Waterloo, or if the Red Army had buckled before the onset of the Russian Winter at Stalingrad? Of course, such moments have not been confined to the military battleground. Consider, for example, the Europe that might have emerged if Anglo-French thinking at Versailles in 1919 had been more like US…