The Crusades were motivated by many things. Among the most significant was to affirm Christian and European identity in the face of Islamic cultural and military successes. A similar motivation underlies the tide of anti-Muslim sentiment.

As Europe forges itself into political, social and economic union, it is also trying to build a common cultural identity out of 15 stubborn nations. To the extent that it succeeds, Europe will inevitably become less tolerant of strong discordant cultural strains within. This not-so-conscious grappling for a common identity is something new. Commentators paint Le Pen as the poster boy for anti-immigrant rage. In fact, he is not representative of this new wave.

Le Pen is not campaigning against foreigners because they are culturally different and disturbing. He’s an old-fashioned thuggish fascist who hates people with different skin colors and gets votes from people who compete with them for unskilled and semiskilled jobs. That makes him easier to explain and more satisfying to hate because we can join a nice clean morality play with a coda of political correctness.

Pim Fortuyn, the extremely appealing anti-immigrant standard-bearer in May’s Dutch elections, is harder to dismiss. And more frustrating, since he is even harsher on immigration than Le Pen. He demands that any government he joins adopt his Zero Tolerance for new immigration. This is the future of European anti-immigrant (and most especially anti-Muslim) sentiment.

Fortuyn is neither anti-black nor even anti-Muslim–so long as these groups agree to become cultural and political Europeans. His argument is more subtle and more dangerous: Muslims who have flooded into the Netherlands in the wake of the 1993 open-border Schengen Treaty endanger the country’s tolerant, modern European culture. These immigrants, he argues, practice an anti-feminist, anti-tolerant, backward-looking religion. What’s worse, he suggests, their version of Islam seeks to convert infidels–and that means the Dutch way of life goes out the door if they succeed.

Mind you, this is not a case he makes in the overheated salons of Amsterdam’s chic neocons. It’s what he says on the stump, and it is having an enormous impact on the political discourse in the Netherlands and elsewhere. According to polling that will be released this week, Fortuyn is now in a dead heat with the two main-party candidates, and he won this position by bringing in voters who have never before taken an interest in politics.

Of course, Fortuyn draws support from Le Pen-like thugs who hear what he says as a polite way of saying he doesn’t like people who look different than they do. But that is not what he’s about. Fortuyn has found a message that mainstream rightist parties will be increasingly likely to adopt, for two reasons. It allows them to tap the anti-immigrant vote without evoking the overt racism of Le Pen. More important, it furnishes them with a new vocabulary, a socially acceptable code for uttering grievances–chiefly the social-welfare costs of carrying new immigrants. Voters understand that if lots more people come to enjoy their benefits, then they will have to cut back benefits to themselves. Either that, or violate strict European Union budget rules. For most, that’s an easy choice. (Keep them out.) But it has been a hard one to put into acceptable words without being called “racist” or “anti-European.”

Until now. By juxtaposing European culture with Islamic culture and using that difference to justify political action against Muslims, Fortuyn is tapping into the deepest roots of European religious history, beginning a few centuries after Islam emerged as an independent political and cultural force. European voters understand that the integration process now underway will weaken individual national cultures across the continent. That’s threatening and makes the idea of a “European culture” more important than at any time in recent history. It opens the door for Fortuyn and his peers to make their case that a strong and unified Islamic culture among immigrants is a clear and present threat.

Indeed, it’s very much like the exhortation Pope Urban II used on the first Crusaders from the pulpit in Clermont. “Race of Franks, you must come to know the imminent peril threatening you and all the faithful. A race from the kingdom of Persia has invaded the lands of Christians.” Urban drove home his point by calling on the spirit of Charlemagne to justify the Crusade: the last leader to unite Europe in anything like the geographic reach that the European Union stands close to achieving today. Hence the resonance with Fortuyn and others. They have opened a debate that will not be easily closed.