SELDOM HAS THE COURSE of European history been changed by a non-politician's throwaway remark in a German-language newspaper on a Wednesday in the dead of the summer doldrums. But on July 28, Princeton historian Bernard Lewis told the conservative Hamburg-based daily Die Welt that Europe would be Islamic by the end of this century "at the very latest," and continental politics has not been the same since.

Days before the third anniversary of 9/11, Frits Bolkestein of the Netherlands, the outgoing European Union competition commissioner, caused an uproar when he mentioned Lewis's remark in the course of an address at the opening of courses at the University of Leiden. Bolkestein warned that the E.U. will "implode" if it expands too quickly. It was a timely topic.

A few days from now, the E.U. commissioner for expansion, Günter Verheugen of Germany, will issue a report on whether to open negotiations with Turkey on E.U. membership. It is expected to be positive. The full commission must vote on the report in December, after which a decade of talks is envisioned. But since the Verheugen report is likely to be positive, and since the commission is expected to rubber-stamp the report's recommendations, and since no candidate state that has begun E.U. accession negotiations has ever been rejected, the process has the look of a fait accompli. Thanks to . . . what? . . . Günter Verheugen's mood, the peoples of Europe are about to see their fate yoked irrevocably to that of the Islamic world. Indeed, the need to forge a solemn bond with Islamic secularism of the sort that Turkey enjoyed after Kemal Atatürk came to power is the reason most often given for the indispensability of Turkish accession.

Bolkestein was thus addressing a continent-wide discomfiture. His speech was long. It was no rant. Alluding to the E.U.'s aspiration to become a multinational state, he drew listeners' attention to the fate of the most recent European power with that aspiration, the Austro-Hungarian empire just over a century ago. Austrians were culturally confident (Liszt, Richard Strauss, Brahms, Mahler, and Wagner were working in Vienna). They were prosperous and proud. The problem was that there were only 8 million of them, and expanding their country's frontiers brought them face to face with an energetic pan-Slavic movement. Once the Empire absorbed 20 million Slavs, it faced difficult compromises between allowing the new subjects to rule themselves and preserving its own culture. Rather like the E.U., the Empire was past the point of no return before it realized it was going anywhere in particular.

Bolkestein asked what lessons Europeans ought to draw from this history, as they consider welcoming Turkey. He then addressed two specific problems. First, that there was no logical end in sight to European expansion--once the E.U. accepts Turkey, it will have no principled reason to reject the considerably more European countries of Ukraine and Belarus. Europe is thus adding instability that it has neither the financial means nor the cultural solidarity to master. The second problem, Bolkestein warned, is that immigration is turning the E.U. into "an Austro-Hungarian empire on a grand scale." He alluded to certain great cities that will soon be minority-European--two of the most important of which, Amsterdam and Rotterdam, are in his own country--and warned that the (projected) addition of 83 million Muslim Turks would further the Islamization of Europe. It was this part of his speech--in which he referred to Lewis's projections--that made headlines around the world: "Current trends allow only one conclusion," Bolkestein said. "The USA will remain the only superpower. China is becoming an economic giant. Europe is being Islamicized."

A kind of chain reaction ensued. Two days after Bolkestein spoke, the Financial Times printed a letter that Franz Fischler of Austria, the outgoing E.U. commissioner for agriculture, had sent privately to his fellow commissioners. Fischler complained that Turkey was "far more oriental than European" and, worse, that "there remain doubts as to Turkey's long-term secular and democratic credentials. There could . . . be a fundamentalist backlash."

Europe's reaction was a collective So now you tell us! Taken together, Bolkestein's and Fischler's remarks seemed symptomatic of the political correctness that suffuses the issue of Turkish accession. A majority of the European parliament is anti-accession, the various national parliaments are against it, and the national populations are overwhelmingly opposed. It is the European Commission that has been driving the process--and now two prominent members of that very body, on the eve of leaving their political careers behind them, were saying it was all a big mistake that nobody dared to talk about. (Perhaps the only thing that infuriates the European man-in-the-street more than such bureaucratic shiftiness is the United States' bafflingly consistent support for Turkish E.U. membership.)

WHAT IS FASCINATING about the Lewis interview that gave rise to this round of European soul-searching is that it was not meant to be specifically about Europe. His interlocutor asked Lewis about developments in the Iraq war, the evolution of the Palestine question, the hopes for liberal democracy in Iran, and the prospects for defeating al Qaeda. (On this last subject, Lewis provided an unsettling answer: "It's a long process and the outcome is by no means certain," he said. "It works similarly to communism, which appealed to unhappy people in the West because it seemed to give them unambiguous answers. Radical Islam has the same force of attraction.") He was equally engaging when he described the European Union's break with the United States in terms of a "community of envy." ("Understandably, Europeans harbor some reservations about an America that has outstripped them. That's why Europeans can well understand the Muslims, who have similar feelings.")

But Europe's own Islamic future came up only incidentally. Asked whether the E.U. could serve as a global counterweight to the United States, Lewis replied simply: "No." He saw only three countries as potential "global" players: definitely China and India, and possibly a revivified Russia. "Europe," he said, "will be part of the Arabic west, of the Maghreb." What seems to have infuriated European listeners is that Lewis did not assert this as a risqué or contrarian proposition. He just said it, as if it were something that every politically neutral and intellectually honest person takes for granted.

Is it? Bolkestein said he did not know whether things would turn out as Lewis predicted. ("But if he is right," Bolkestein added, "the liberation of Vienna [from Turkish armies] in 1683 will have been in vain.") Bassam Tibi, a Syrian immigrant who is the most prominent moderate Muslim in Germany, seemed to agree with Lewis's diagnosis, even while rejecting his emphasis. "Either Islam gets Europeanized, or Europe gets Islamized," Tibi wrote in Welt am Sonntag. Having spent much of the past decade arguing for the construction of sensible Islamic institutions in Europe, Tibi seemed to warn that Europe did not have the ability to reject Islam, or the opportunity to steer it. "The problem is not whether the majority of Europeans is Islamic," he added, "but rather which Islam-- sharia Islam or Euro-Islam--is to dominate in Europe."

Christopher Caldwell is a senior editor at The Weekly Standard.