This from the end of a Martin Peretz article, no longer available, in a Commentary chain of articles identifies what I think is the key issue:

What the Bush Doctrine has not dealt with is the issue that has been forced, albeit very reluctantly, upon Europe. It is not only a matter of sleeper cells. There is the more basic question that faces all Western democracies, some more (France and the UK, Belgium and the Netherlands, Spain, maybe Germany), some less (us, if we are lucky): what are the standards for citizenship in a national community?

This is not an idle question. “Admission and exclusion,” writes Michael Walzer in Spheres of Justice (1983), “are at the core of communal independence. They suggest the deepest meaning of self-determination. Without them, there could not be . . . historically stable, ongoing associations of men and women with some special commitment to one another and some special sense of their common life.” Such considerations do not dispose of the matter, but they are central to the survival of democratic norms. Does mass immigration of one group or another endanger the rules and the motifs of democratic politics? Does it imperil the habits, so painfully attained over the generations, of social tolerance, sexual equality, achievement through study and work? Does it burden society with the fires of the old country’s hatreds?

These questions were raised, some only inferentially, on Dream 2 TV, an Arabic channel, by Khaled Abu al-Fadhl of UCLA law school. He didn’t evade the central issue: “Is the Muslim who is an American citizen . . . really an American citizen who loves America, or does he belong to a fifth column, with loyalties that lie elsewhere?” I do not know the answer to this question, and there are many impediments to seeking it, including the legitimate desire to keep xenophobia out of the discussion. But I am glad the issue has been put into the public arena.

A lot of ideas have been buzzing in the bean on solving the problem identified here by Peretz, essentially three types of engineering: intellectual (theological), social (moral) and physical (scientific). Focus is on design of a Prayer Hall for all believers located, ideally, near town/city vital but not commercial centers in park-like settings. These would supercede churches, synagogues, temples, mosques, chapels, etc. They would be genuinely ecumenical in the sense of concentrating on what all the religions have in common with respect to symbols (candle and flower) and activities (prayer, study, calm discourses on spiritual questions, reading/hearing scriptures and inspirational literature — all quiet activities, the quieter the better). They would be run by lay and scholars jointly, no liturgies, which are of particular religions.

There has to be a tangible focus in every town and city, endowed straight up as by a Rockefeller at Riverside Church and the UN or by a Carnegie as with the libraries, for the impulse to transcend partisanship in the name of religion, which admits of no partisanship.  Significant that no modern billionaire is interested in this forward-looking necessity of peace, only in self-promotion and commercial monopoly.  None has the self-less spirit of Carnegie or even the civic spirit of JDR II.  It’s all private interest for moderns.  Not exactly heartening.

AMDG