Paris-based writer Simon Kuper recently took an updated look at this problem, and found a very different picture. First, Muslim minorities in Eruope have not proven immune to the demographic transition which has swept the Third World and more recently arrived even in the Islamic lands:
In Belleville you see women of Arab origin pushing prams. But you also see the white French artistic couples who have recently colonised the neighbourhood pushing Bugaboo strollers. That Muslims are grinding out babies ready to take over Europe is an outdated canard. The Eurabia authors worry about declining European fertility, but in fact the Muslim decline is much sharper. In 1970, women in Algeria and Tunisia averaged about seven children each. Now, according to the CIA World Factbook, they average fewer than 1.8. The French rate is almost exactly two.....At last count Algerian women living in France averaged an estimated 2.57 children, or only slightly above the French rate. Moreover, the fertility rate of north African women in France has been falling since 1981. Eurabia is not a demographic prospect.
(Yes, you read that right -- the fertility rate in Algeria and Tunisia is now lower than the French rate, which mostly reflects the rate of the non-Muslim 92% of France's population.) I have noted this phenomenon before in connection with Denmark (see also here and here). In western Europe as a whole, the indigenous birth rates have crept upward a bit (following a similar pattern to the US a decade or two earlier, where birth rates fell and then rose again, apparently due to career women postponing childbearing), while Muslim birth rates have plummeted. The indigenous and Muslim rates are converging; soon the differences between them will be negligible. Even then, Muslims will produce a disproportionate percentage of the children in each country for a while, because a larger proportion of the Muslim population is in its young-adult child-producing years while the indigenous population is older, but eventually this effect too will disappear.
Even more important and more hopeful is Kuper's second major observation: the Muslim population in western Europe is proving much more susceptible to assimilation than previously thought. Obviously this phenomenon is much more difficult to quantify than birth rates, but the pattern seems clear:
Probably less than 5 per cent of French Muslims attend mosque every Friday.....Farhad Khosrokhavar, director of research at France’s Ecole des Hautes Etudes en Sciences Sociales, estimates that 15 to 20 per cent of French Muslims do not practise Islam at all......Poverty, not religion, is the main preoccupation of French nominal Muslims, polls consistently show. In a survey by the Pew Research Center in 2006, for instance, 52 per cent of French Muslims said they were “very worried” about unemployment. Only about a fifth said the same about the decline of religion or the influence of pop culture. Few French Muslims profess to care much about foreign political issues such as the Israeli-Palestinian conflict.....
Laouati told me her parental home was like a “little Algeria”. But Dreux Arabs younger than her had become “petits français”, she said. “They are much better integrated. They know very little of Maghrebian languages. They all watch French TV. Arab TV would bore them to death.”....Muslims in France consistently report strong identification with France. In a poll in 2005 by the US state department, for instance, 95 per cent expressed a favourable overall opinion of France. In a Gallup poll two years later, 46 per cent of Parisian Muslims said they identified “very strongly” or “extremely strongly” with France – exactly the same percentage as those in the national population.
You need to read Kuper's entire article to get a full sense of what he's talking about. It's clear that religion is still far stronger among European Muslims than among the post-Christian mainstream societies; but it is much weaker than it was among those Muslims' ancestors when they arrived in Europe, and much weaker than the Eurabia alarmists thought it could become. There is a great deal of muddled talk about building an identity "both Muslim and French", but this is a typical transitional phase, comforting to people who are on the way to full assimilation but prefer to believe otherwise. And as Kuper notes, Sarkozy's administration is taking a far more active role in enforcing assimilation than its predecessors did.
The logical end-point of the assimilation process, of course, is de-Islamization -- giving up Islam entirely. This is even harder to quantify, since writers tend to reflexively classify anyone whose parents or grandparents were Muslim as being a Muslim, regard- less of what he actually believes or doesn't believe. Nevertheless, de-Islamization is happening and is even becoming visible, at least in Britain, despite the obvious danger from hard-liners (Islamic law mandates the death penalty for anyone who leaves Islam).
None of this is to deny the fact that Islam in Europe presents a real danger. It has brought terrorist attacks, riots, and an upsurge in violent crime in nations where such crime used to be rare (though all these problems seem to have subsided somewhat over the last few years, partly due to crackdowns by exasperated Europeans). Civilized legal systems are being confronted with sick medieval barbarities like honor killings and clitorectomy, and in many cases have been shamefully timid in opposing such things. Militant Muslims are evolving into a social force similar to our Christian Right, demanding official recognition of barbaric religious law and threatening the rights of homosexuals and women, and opposing secularism in general; on this phenomenon, see here and here.
But the demographic tide is turning. Militant Muslims in Europe are shrinking to a hard core of the most assimilation-resistant. Like some militant Christian fundamentalists in the US, they may actually become even more deranged and violent and dangerous as they realize that their dream of becoming the dominant force in society has been irrevocably dashed. European governments must, and probably will, take a far tougher line with them. But they are, and will remain, a manageable problem, not the bringers of the apocalypse.
The point is that Muslims in Europe are reacting pretty much like people from a blackward society normally react when they are plunged into a far more advanced and attractive culture; over time they absorb that culture, and are absorbed by it. The process has been slower than with immigrants in the US, partly because Islam makes Muslims resistant to assimilation and partly because European countries lack our experience with large waves of very culturally-different immigrants and are less geared to assimilating them. But in the end the result will be the same.