Since 9/11, Western Europe's growing Muslim population has been the focus of debate on issues ranging from immigration policy to cultural identity to security. Several incidents in recent years have increased tensions between some Western European states and their Muslim populations: the 2004 Madrid and 2005 London attacks, the 2004 ban of the head scarf coupled with recent calls to ban the "burqa" in France, the 2005 Paris riots, the 2006 Danish cartoon incident, and several high-profile murders. 

Despite signs that Muslims are beginning to succeed in business and academia in countries such as France and Germany, many analysts say most of Western Europe's Muslims are poorly integrated into society. They cite closed ethnic neighborhoods, high crime rates in Muslim communities, calls for use of sharia law in Europe, the wearing of the veil, and other examples as evidence of a conflict with European values. Reacting to the November 2009 vote to constitutionally ban minarets in Switzerland, Oxford University scholar Tariq Ramadan wrote in the Christian Science Monitor: "Over the last two decades Islam has become connected to so many controversial debates ... it is difficult for ordinary citizens to embrace this new Muslim presence as a positive factor." Fears over a possible major demographic shift toward Islam as well as ongoing Muslim assimilation problems highlight the continuing divide between Europe and its Muslim population.

After World War II, Western Europe welcomed a large immigrant labor force to help rebuilding efforts. Later more immigrants were admitted to meet rapid economic growth, allow family reunification, and provide asylum. At first, concerns over the influx of workers from other countries were "largely about race and ethnicity," notes Ceri Peach, a professor of social geography at Oxford University, in a 2007 report (PDF) from the Center for Strategic and International Studies (CSIS). The rise of Islamic regimes after the Iranian revolution in 1979--and more recently the increase in terrorism--has called attention to the fact that many of these immigrants were not only ethnically different but also Muslim.

Western Europe has experienced an increase in immigration from all around the globe in the last decade. The European Union's June 2009 strategy report on immigration (PDF) shows a total of 18.5 million registered non-EU nationals and an estimated 8 million illegal immigrants living in the European Union.  According to a 2008 Brookings study, the EU countries with the largest percentages of Muslims are France at an estimated 8 percent, Netherlands estimated at 6 percent, Germany at 4 percent, and the United Kingdom at 3 percent of the population. And Muslim populations exceed 20 percent in some major EU cities.

The total Muslim population in Western Europe overall is about 20 million of the EU's 500 million residents. Some experts contend the continuing influx of immigration from Islamic countries, along with higher immigrant birth rates and lower native European birth rates, mean Muslims in Western Europe could significantly increase in coming decades. However, the CSIS report says that past estimates of growth in Muslim populations seem to show inconsistencies and should be "treated with great caution," and argues that the speed of population growth "in countries with good data" is less than estimates had suggested.

The largest demographic change could come from Turkey, currently discussing entry procedures with the European Union. That alone would increase the Muslim population in the EU by some 70 million. But Turkey's EU accession is increasingly in doubt, which Justin Vaisse, a fellow for European Studies at the Brookings Institution, says makes speculation about any impacts difficult.

Overall, Muslims face a number of challenges on integration and assimilation:

• Poverty and Segregation. Experts say Muslims in Europe are more likely than the EU general population to be poor and live in segregated, crime-prone neighborhoods, according to a 2007 report from the Centre for European Policy Studies. A 2005 Pew report concludes it appears "that segregation is both natural and problematic." Dalia Mogahed, executive director of Gallup Center for Muslim Studies, points out that similar "to minorities in the United States, where one lives is often dictated by socioeconomic realities (Guardian) rather than cultural preferences." Vaisse concurs, noting he doesn't "know anyone living in the ghetto that wants to be there."

  However, other analysts find some Muslims also self-segregate for reasons such as language barriers and different cultural norms, such as prohibitions against drinking. Jocelyne Cesari, a Harvard professor and author of 2004 book When Islam and Democracy Meet, argues in order to protect themselves, some Muslims seek closed communities similar to the Amish community in the United States. She says Europeans need to learn to differentiate between religious "conservatives and Jihadis."

  High crime rates and dependency on the social welfare system also contribute to European feelings that there is a Muslim problem. Cesari says many Muslims suffer from the "dysfunctional attitudes" and behaviors of Europe's poor. She points out that the more involved Muslims are with their religion the less likely they will be to participate in behaviors such as truancy, drugs, and criminal activity. But this presents another problem: "What we don't want is the kind of Islam that saves the individual but doesn't help them accommodate to society," she says.

  Lack of economic opportunity among poor Muslim populations has also contributed to tensions in recent years. Vaisse points out the 2005 Paris riots had nothing to do with religion and everything to do with jobs and economic opportunity. EU Muslims tend to have high unemployment rates, but it is unclear whether they are significantly higher than non-Muslim ethnic minorities. Unemployment statistics in 2004 for Britain show that other than Indians, unemployment rates for all non-white ethnic groups were generally higher than white ethnic groups. The statistics also showed unemployment rates for Pakistani and Bangladeshi women were nearly twice as high as for other minority women. A 2009 report from the Quilliam Foundation, a London-based think tank focused on counter-extremism issues, says polling of South Asian Muslim women found that unemployment was less because of religion and culture than because of poor job and language skills (PDF), and a lack of childcare and confidence.

  Some experts believe that middle-class Muslims are much more likely to favor assimilation. For example, a 2007 Pew poll showed Muslims in the United States, whose incomes and education are in line with the general public, "are highly assimilated into American society."

• Religion and Identity. Muslims in Germany, Britain, and France were twice as likely as the general public to consider religion a significant part of their daily lives, according to a 2007 Gallup poll. A Pew 2006 poll shows that Muslims in Europe are much more likely to identify themselves by their religion before their nationality. However, the Gallup poll also shows that religious affinity does not make Muslims less likely to identify with their host countries.

  Even some Muslims who aren't particularly religious may be drawn to projecting a strong Islamic identity in response to feelings of isolation and their perceptions of the moral permissiveness of Western culture. Muslim diversity in Europe also means there is no monolithic version of Islam being practiced. Some analysts say since culture plays a large role in how Islam is translated into daily lives, there is hope a stronger Euro-Islam identity will emerge as Muslims continue to grow into European culture. "Muslims in Europe are working hard to try to find ways to educate their own communities and talk about the balance between being Muslim and Western, not Muslim or Western," says Farah Pandith, U.S. envoy to Muslim communities.

• Culture and Democracy. Some argue that Muslim culture is at odds with Europe on issues such as freedom of expression, the rights of women, and the separation of church and state. Financial Times columnist Christopher Caldwell, in his 2009 book Reflections on the Revolution in Europe: Immigration, Islam and the West, concludes: "Europe finds itself in a contest with Islam for the allegiance of its newcomers. For now, Islam is the stronger party in that contest, in an obvious demographic way and in less obvious philosophical way."

  Caldwell points out the cultural disconnect Islam is causing for Europeans: On the one hand, Europeans expect a strong division between church and state. On the other, Europeans' aspirations for tolerance impede their ability to criticize Islam in the same way they have historically criticized Christianity. There have been numerous cases of Muslims using Europe's hate speech laws to defend against what they consider defamation of Islam. Meanwhile, cases such as the 2004 murder of Theo van Gogh (BBC) for his film "Submission," critical of treatment of women in Islam, are considered evidence of intolerance by Muslims toward freedom of expression.

  Cesari and Brookings' Vaisse note understanding the line between criticism and bigotry will take time for all Europeans. Cesari contends Muslims need to learn that criticism is part of the democratic process and that the "inability to hear one another" may be the greatest problem of the Euro-Muslim debate. Following the 2005 Danish cartoon incident, which sparked riots in many Islamic countries, Vaisse points out Muslims in Europe largely used legal means to show their displeasure. This, he argues, is a sign Muslims in Europe believe in democratic institutions.

• Discrimination and Bias. A 2006 report from the EU Monitoring Center on Racism and Xenophobia found that Muslims face discrimination in all aspects of life (PDF), from housing to employment opportunities to education to cultural practices. For many Muslims, being ethnically different and immigrant is often a greater challenge than their religious differences, says Vaisse. "As Muslims in Europe are overwhelmingly non-white, ongoing racial disharmony naturally impedes integration," wrote Tim Winter (PDF), a lecturer of Islamic studies at the University of Cambridge, in 2007.

  So inflammatory were the campaign posters against the minaret in Switzerland, they were banned as racist in some Swiss cities. The attention and vehemance the media and some politicians place on symbolic issues like the minaret and the head scarf foster more alienation in Muslim communities, some analysts say. Muslims have also pointed out the media's double standard, which made much of van Gogh's murder, but was largely silent on the 2009 murder of a Muslim woman--dubbed "the veil martyr"--and shooting of her husband in a German courtroom.

  Though intolerance is not restricted to one group, Muslims have become an easy target because of terrorism, says Akbar Ahmed, chairman of Islamic Studies at the American University. But he notes bias also flows in the other direction, saying Muslim anti-Semitism in Europe is "constantly on the boil."

• Terrorism and Security. The focus of the debate over Muslim immigration and integration is conjoined with fears of radicalism underscored by terror attacks in London and Madrid and a host of other incidents and arrests. But in some cases, the culprits were European-born and well-assimilated. Julianne Smith, director of the Europe Program at CSIS, argues in the 2007 report (PDF) that European countries' approach to terrorism and radicalism fall into three broad categories: integrating Muslim minorities, slowing the recruitment of potential extremists, and seizing and arresting terrorist operatives. Robert S. Leiken, director of the Immigration and National Security Program for U.S.-based Nixon Center, says overall European countries have done a relatively good job at monitoring and controlling terrorism.

  A 2005 report from the nonpartisan U.S.-funded Congressional Research Service contends diversity among Europe's Muslim population may help impede a "sharply developed tendency toward radicalism," but warns of the dangers of disaffected Muslim youth. Leiken argues that there are differences in how extremist the Muslim communities across Europe are, with Britain's being the most worrisome (PDF).

Scholars point out that cultural debate over Muslims ignores the profound demographic changes in Europe because of increased immigration from all over the world. "At the very moment Europeans find themselves asking, in a globalizing, migratory world, 'What are our roots?,' 'Who are we?,' 'What will our future look like?,' they see around them new citizens, new skin colors, new symbols to which they are unaccustomed," writes Oxford's Tariq Ramadan. Harvard's Cesari says this "cultural malaise" cannot be blamed on Muslims and instead countries need to "completely rephrase" what European and national identity means. Immigration policy in Europe currently focuses on monitoring illegal immigration and addressing the burden of asylum seekers.

Both Vaisse and Mogahed argue the policy discourse on the best way to integrate Muslims should be shifted from cultural differences to socioeconomic ones. Cesari suggests public schools should teach the Islamic contributions that have led to modern Europe to show that Islam is not as foreign as some perceive. Experts say the media and European politicians need to tone down the rhetoric on Muslims as a group--particularly on terrorists--if there is to be any hope for greater integration and assimilation. Meanwhile, some countries are beginning Imam training programs at universities as a way to promote assimilation. "We have 2,600 mosques in Germany, and I don't know a single imam who has a European education," political scientist Bassam Tibi told Deutsche-Welle. "How can they show the Muslim who live here how to live?"

To monitor radicalism, Leiken says good intelligence within communities is needed and policymakers should learn to make distinctions, not only among Muslims but among Islamist groups, some of which could be helpful in combating terrorism.