The two countries have never been the easiest of allies, but now it is almost as if they were at war. Yet France and America are curiously alike, and perhaps that is part of the problem. The most important common factor is the revolutionary birth of their democracies.

In the 18th century the French and the Americans were still full of mutual admiration. The French were inspired by the American Declaration of Independence, and Benjamin Franklin was happy to have his infant son blessed by Voltaire in the name of liberty.

The differences between revolutionary France and revolutionary America soon became apparent. Whereas the US founding fathers sought to guard individual liberties by limiting the powers of the State, the French State took on huge powers as an expression of the will of the people: the difference between Rousseau and Jefferson. Nonetheless, both were convinced that they represented universal values, and it was their manifest destiny to spread them across the world.

The French mission ended in the bloody fields of Waterloo. But the old missionary zeal survives in its now forlorn attempts to run the European Union, its not always honourable interventions in Francophone Africa, and above all, in its constant poking in the eyes of Anglo-Saxons.

If the French mission to shape the world is more or less over, the American one is still blasting with both barrels. In many ways, we Europeans should be grateful. Without America, we might well have ended up living in a fascist empire. The world of international institutions that Europeans now rely on owes everything to Woodrow Wilson's dreams. American idealism (as well as enlightened self-interest) was also responsible for the Marshall Plan, the restoration of democracy in Germany and Japan and, probably, the collapse of the Soviet empire.

But it was also the driving force behind less successful ventures, such as the war in Vietnam, another task once shared by the French. Unless one believes, like Noam Chomsky, that the war was fought for the sake of corporate interests, that too was at least partly the result of American idealism. Presidents Kennedy and Johnson thought they were protecting Asian dominoes from falling to communist tyranny. Remember that the Quiet American was not a heartless monster, but a missionary for American democracy. Like many US political missionaries, he was a kind of democratic Trotskyite, who caused mayhem without realising why.

Vietnam put a big dent in American self-confidence. Realism marked the 1970s and 1980s. In a way, Henry Kissinger’s hardnosed realpolitik matched the desire of liberals to rein in America's ambitions to change the world. But this began to change under Ronald Reagan, when neo-conservative intellectuals, many of whom had been Trotskyites, demanded a revolutionary programme to combat evil empires.

This was a departure for Republicans, who had rarely been interested in saving the world. That was always more of a Democratic project. Republicans wanted stability, and to be left alone to take care of their economic interests. The world outside was a place to do business in, not to change through democratic revolutions. But the New Right was gradually injecting the zeal and rhetoric of the Old Left into Republican politics.

The true nature of this enterprise was spotted by Daniel Cohn-Bendit, the “Danny the Red” of May 1968. In a recent meeting with Richard Perle, he said that Perle reminded him of his own student days in Paris. Perle, he exclaimed, was a Bolshevik. All his life, Cohn-Bendit had been fighting Bolsheviks on his left. Now they were on his right.

The neo-cons’ most zealous ambitions never became mainstream, however, even under Reagan; and Bush the Elder, a typical country-club Republican, was quite cautious, despite his talk of a new world order. When his son ran for election, he too promised to be careful, to have a “humble” foreign policy. This humility changed after September 11. Finally, the revolutionaries hovering around the Pentagon, writing for such journals as The Weekly Standard, and holding forth at such forums as the American Enterprise Institute, got what they wanted: a revolutionary war.

And this is largely why we fought in Iraq. A peculiar coalition of evangelical Christians, neo-conservative intellectuals, and former leftists, have revived America’s idea of its manifest destiny to change the world. Paul Berman, a former leftist who jumped on Bush’s bandwagon, thinks the war against Saddam was like Lincoln’s campaign to free the slaves of the South. In his new book, Terror and Liberalism, he claims that European democracy is cynical, soft and bloodless, because Europeans don’t share America's ambition to revolutionise the world.

It does explain why the French are the most vehement opponents of the US. For France is the only European nation that still thinks it represents universal values. And the French no longer believe they share them with the US. When you have competing views of universalism, fireworks are inevitable.

The Franco-American rift is ominous for the future of our democracies, for it has split the West. The damage will not be easy to repair, but the French, and especially the Americans, would do well to heed the words of a great statesman, Talleyrand: “Toujours pas trop de zèle” (Above all, not too much zeal).

Ian Buruma is author of Voltaire’s Coconuts: or Anglomania in Europe

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