Western Europe has a Muslim problem, and it is particularly acute in Great Britain, which is more intimately linked to constitutional traditions and procedures. The French are quietly aghast at the presence of 5 million Muslims in their midst and are endeavoring to cope. But that is a country which is enjoying (or accommodating) its Fifth Republic. If a Sixth Republic were introduced in the years ahead, one would not think the event mortally destabilizing.

In Britain the situation is different. For one thing, we have there the mother of parliaments, which has weathered tumult and war and devolution, without any sense that the vital organs of British life had been anachronized. Consider only the monarchy. It is easy to think of it as Punch and Judy, but it is more than that, never mind the annus horribilis about which the queen complained. And that year was followed by others in which she breathed a sigh of relief when a member of the royal family was not divorcing, renouncing a title or dying in a French tunnel with her lover.

Forget all of that. What would never happen anywhere in the world, if the queen were to appear, is a failure to curtsy or, however slightly, to bow one's head.

What we have, said a British patriot in one of the darkest days of World War II, is "the British way of life." That way of life is ever so vulnerable if examined under lacerating glass, and indeed that is exactly what happens every week at the Oxford and Cambridge Unions, where the students tear themselves and their country to pieces for a noisy evening and then submit decorously to the ruling of the union's president, and get on with the British way of life.

But the threat to it is not, this time around, in the shape of a continental army threatening invasion or Nazi bombers darkening the sky. The threat now is the Muslim immigration. There are fewer Muslims in Britain than in France -- 2 million -- but that's still a lot. For many years Britain faced the problem of its commitment to members of its empire: Any citizen could leave Malaysia or Pakistan or India or Jamaica and simply show up, declaring himself a British resident. That problem was hotly debated in the days of Enoch Powell, when he insisted, departing England for a constituency in Northern Ireland, that some limits had to be observed or the British way of life would disappear.

The crisis is focusing now on the schools. The Muslim community has demanded its own schools. Wherein what, exactly, will be taught?

There are many interpreters of the true meaning of the commandments of the Quran. But among them are men and women who are prepared to end their own lives for the satisfaction of defying the British way of life. Four such persons, in the summer of 2005, attached themselves to bombs and blew up handy British targets, including three Underground trains. Continued...