One should not underestimate the power of the idea of European unity to fascinate political elites. During a visit last year to Poland, I met an eminent professor who said of the euro: "We want to join the boat even though it is sinking." Radek Sikorski, the Polish Foreign Minister, some time ago broke with his British Eurosceptic friends and fellow members of the Bullingdon Club (a nursery of statesmen in which Sikorski, Boris Johnson, Cameron and, some years later, Osborne all played). In his tremendous speech in Berlin on November 28, 2011, Sikorski called on Germany to help lead Europe into a united federation which will do whatever is needed to save the euro, while leaving most other things to the member states. Sikorski's speech rose to the level of events in a way that few do. Unlike most European leaders, he examined the most relevant precedent, namely the formation of the United States. He wishes a reformed European Commission to acquire draconian powers to supervise national budgets, while itself being subject to a more powerful European Parliament. In my view, this cannot work, for reasons explained authoritatively by Larry Siedentop in Democracy in Europe, where he observes of the gathering in Philadelphia in the summer of 1787: "There was tacit agreement among the delegates that some functions of the British Crown . . . were only temporarily in abeyance—waiting, so to speak, for a central authority to take them over again." Europe lacks this ghost of a once legitimate authority. Nor can it draw on the established habits and attitudes which were of such value, as Alexis de Tocqueville recognised, to the founders of American democracy.

After Cameron had spoken, Guido Westerwelle, the German Foreign Minister, who like Sikorski is a member of the Future of Europe group of 11 foreign ministers which wants closer integration, took it upon himself to retort, in a prosy manner: "There can be no cherry-picking." As a number of German commentators pointed out, Berlin is no more averse to cherry-picking than other countries are. When Merkel decided to switch off Germany's nuclear power stations, she did so without asking what effect this might have on European energy policy, or indeed on French energy policy.

There is no end to the piety of Westerwelle, a former leader of the Free Democrats. As this Teutonic Nick Clegg also said: "Never again can we allow the loose spending habits of individual nations to weaken the foundations of the European house." By the time he discovers that ordering other people around will destroy rather than preserve the European house, it will be too late.  

But many thoughtful Germans, including Merkel, realise that the EU cannot go on as it is, and find what Cameron is saying more interesting than anything coming out of Paris. It always struck me, while living in Berlin in the 1990s, that there were at the very least considerable affinities between the British and the Germans. Neither country will in the end tolerate having its affairs run by a Napoleonic bureaucracy established in Brussels as an extension of the French state. Germany has a beautiful modern constitution, Britain has a beautiful ancient constitution, and neither is compatible with the imposition of European rule, unless and until that rule can be given the kind of elevated form which the Americans devised for themselves in Philadelphia. That is unlikely to occur in our lifetimes, for as Cameron said in his speech, there is no European demos and democratic legitimacy still flows from national parliaments.