MOST AMERICANS HAVE FACED the war on terrorism knowing that we may have to "go it alone" at some point. According to this unilateralist school, the anti-Taliban, anti-al Qaeda, anti-terrorism coalition we've assembled will--as the bombing toll in Afghanistan rises--gradually erode until there's no one left in it but us and the British. First the Arab nations will call it quits, then the rest of the Islamic world. Finally, Europe will abandon us, led by France.

Apparently, no one thought to ask the French about that. In an extraordinary and little noticed series of polls over the past month, the Paris-based public-opinion research firm Ipsos has found that not only are the French on board for the war--they're crazy about it.

Granted, the country's leadership has sent mixed messages. While President Jacques Chirac has offered the country's "unconditional" support, Prime Minister Lionel Jospin, who's supposed to keep his nose out of foreign affairs but is running against Chirac next year, has been hedging since the morning of September 11. To his enduring disgrace, Jospin was warning America against overreaction even as survivors were still screaming in the Trade Center rubble.

But there is no such division among the French public: 68 percent described themselves to Ipsos as wanting France to participate in the American war against terrorism, versus only 34 percent opposed. This is not soft support: 61 percent back involvement even if it means risking "terrorist reprisals on French soil"; 46 percent back involvement even if it means a "significant number of casualties" among French troops.

Why are the French so gung-ho? There's an optimistic and a pessimistic explanation.

The optimistic one is that they've simply come to their senses and are behaving as loyal allies. That's what our new ambassador to France, the billionaire California Bushie Howard Leach, would like to think. "The response of the French government," says Leach, "has been absolutely marvelous."

The pessimistic explanation is that the West is on the verge of exactly what the Bush administration is seeking to avoid--the kind of "clash of civilizations" that Harvard political scientist Samuel Huntington has described--and that the Europeans are just better-equipped to see it than we are. Specifically, it is possible that French citizens are playing out their animosity towards the country's 5 million Muslims, most of them North Africans and Frenchmen of North African descent.

Foreign policy can create mammoth tensions with European Islamic immigrant groups, as the Gulf War showed. In 1991, the Supreme Council of British Muslims scandalized the British public when it voted unanimously to explicitly support Saddam Hussein and Iraq against John Major and the rest of the Western coalition. Perhaps because Muslim groups learned how potentially dangerous it would be, there has been no such in-your-face defiance of British public opinion in the wake of the WTC attacks.

But spectacular instances of such defiance have taken place in France since September 11. Immigrants in certain of France's housing projects greeted news of the attacks with Palestinian-style cheering and jubilation. That unnerves people in two ways: It shows that France is a place where covert al Qaeda operatives could find sympathy and shelter. And it indicates that the instant large-scale terrorism hits a European country with a large and unassimilated Islamic population, the reaction among the non-Muslim public could be explosive. We might even have to warn Lionel Jospin to keep his cool.

Christopher Caldwell is a senior editor at The Weekly Standard.