True, some of them did make it, sometimes against heavy odds. Some of these successful Muslims are showing greater toughness and realism vis-à-vis their communities than their non-Muslim counterparts. Ahmed Aboutaleb, the mayor of Rotterdam, holds both Dutch and Moroccan nationality. This has not prevented him from advising those of his coreligionists who did not like it in the Netherlands to go back to their country of origin. Job Cohen, the  former mayor of Amsterdam, would hardly have dared to make such a statement, not in any case before he resigned as mayor to become head of the Dutch Labour Party. Since then, he has been considerably more outspoken. Nyamko Sabuni, an 

African Muslim and the Swedish minister for gender equality, suggested a medical investigation of Swedish schoolgirls to find out the extent of genital mutilation. Nothing became of her initiative but it is unlikely that any of her Swedish-born colleagues would have dared even to mention a subject like this. 

The decisive issue is not the numbers but the integration of the new immigrants. About half of the newcomers — more in some countries, fewer elsewhere — have expressed their wish to adopt the values and customs of their new homes, but half are rejecting them as incompatible with Islam. The authorities in some countries (notably France and the Netherlands) claim that Muslim integration has been more successful than generally believed. No major terrorist attacks have succeeded in Europe in the last five years since the London and Madrid bombings and the murder of Theo van Gogh. However, these claims cannot always be taken at face value. In Germany, the optimism is based on an investigation of all immigrants, including the many who came from Russia. In England, glowing accounts have been published about certain state-supported Muslim schools. But on closer investigation, it appeared that they were preaching that most things British were sinful, including Shakespeare and cricket. Many dozens of young Muslims from Germany, Denmark and the UK have gone to fight the infidels (or their own brothers) in Afghanistan, Pakistan, Somalia, Yemen and elsewhere. But the issue is not terrorism, important as it is, but integration or the "rejuvenation" of Europe. 

What then of the second and third generation? A well-known Berlin imam has said that "the road to the mosque is long and the temptations are many". It is not clear what temptations he had in mind: probably not Western political philosophy but those of the flesh such as the less savoury aspects of contemporary Western civilisation — drugs, drinking, pornography. While the second and third generation of Muslim immigrants is generally more radical, this may well change over time. But it is unlikely to change soon. It may take several more generations. Islam once had a great civilisation and there could be a revival after centuries of stagnation and decline. But what kind of "rejuvenation" can Europe expect in the years and decades to come?