Muslim faithfuls take part in a special morning prayer to start their Eid al-Fitr celebrations on a field at the Prospect Park in Brooklyn borough of New York, July 17, 2015. Jewel Samad/AFP/Getty Images

Ten years ago, the U.S. embassy in Paris sent a secret diplomatic cable to Washington foreshadowing the unrest France would face in the decade to come: "France not only has a problem with integration or immigration; it also needs to act to give Muslims a sense of French identity," the cable dated Aug. 17, 2005, read. It was prescient of what would happen next: Later that year, disaffected Muslim youth initiated violent riots in the suburbs of Paris, and things have only deteriorated since. After the deadly terrorist attacks that killed 129 and injured hundreds more in Paris on Friday, authorities discovered that at least five of the attackers were French nationals who had been radicalized right at home in the City of Light.

Some 5 million Muslims live in France -- about 7.5 percent of the country’s population -- one of the largest Muslim populations in Western Europe. After the horror of the coordinated terrorist attacks on six sites in Paris last Friday, a climate of suspicion once again engulfs Muslims living in the Western world -- and French citizens and politicians alike are grappling with how to respond to homegrown threats. But experts say that the conditions of Muslims in some European countries can create fertile breeding grounds for extremism, whereas societies with more-integrated Muslim populations like the United States are less susceptible.

“In a very broad sense, you have the same communities in Europe and America. Both are Muslims living in the West. But in fact, there are huge sociological differences between the two groups. Most importantly, the relationship between Europe and its Muslims is one rooted in colonialism, whereas the U.S. has no previous history with its Muslim populations. So [in Europe] there is some of the residue of racial and cultural prejudices of the colonial era,” says Akbar Ahmed, chair of Islamic Studies at American University’s School of International Service and the author of several renowned field projects on Muslims, including “Journey Into Europe: Islam, Immigration and Empire.”

The result is two very different communities: One in America that is hopeful, affluent and better assimilated, versus one in Europe, particularly in countries like France, that exists on the periphery of society, both economically and socially. It’s that marginalization of European Muslim communities that can leave certain members vulnerable to recruitment attempts from groups like ISIS.

One of the main differences stems from the makeup of Muslim groups in European countries compared with those in the United States. Estimates vary, but Muslims in the United States account for 1 to 2 percent of the total population -- yet there is no one ethnic group that dominates: Muslims hail from 77 different countries in the Middle East, South Asia, Africa and Europe. That’s a stark contrast from Europe, where the Muslim populations are more homogenous and typically made up of residents of former colonies. For example, the Muslim community in the U.K. is dominated by Muslims of South Asian descent, while three-quarters of French Muslims are mostly of Morocco, Algeria or other North African origin, according to the Brookings Institution.

A young Muslim woman stays outside the French Embassy in Berlin among flowers left by mourners commemorating the victims of last Friday's terrorist attacks in Paris. Carsten Koall/Getty Images

“In Europe, pockets of Muslims are isolated by country of origin, which hampers integration. That keeps Islamic identity tied to a home country and so the community is more insular. The umbilical cord is still there,” says Shahed Amanullah, who has worked as a senior adviser at the U.S. Department of State on issues surrounding Muslim youth around the world. “In America, no one group that dominates. It’s not an affinity-based community but a value-based community.”

Amanullah adds that in Europe, especially in places like France, Muslims tend to be ghettoized, living in often run-down Muslim neighborhoods known as banlieues that are isolated from mainstream society, whereas in the U.S., American Muslims are dispersed throughout the country, with very few “Muslim-only” neighborhoods -- which also forces assimilation and integration.

“The Muslim community in France is marginalized, impoverished, constantly humiliated. They live as second-class citizens, in slums, their kids have no jobs, they’re insulted whenever they step out of their areas. They don’t have a sense of hope,” says Ahmed. “That’s not true in the U.S. However bad the situation may get in the United States, the community doesn’t lose hope. Muslims there may feel that there is some prejudice against them but that they can still succeed.”

Affluence And Optimism

Muslim Americans mirror the optimism of many American communities: Nearly three-quarters surveyed believe that most people can get ahead if they work hard, according to a comprehensive Pew Research study on Muslim American demographics and attitudes. And they are as likely as the general American population to report household incomes of $100,000 or more (14 percent of Muslims, compared with 16 percent of all adults). They are generally satisfied with their economic lot in life: 46 percent said they were in excellent or good shape financially, compared with 38 percent of the general public who said the same. And they’re almost as likely as the general public to have graduated from college (26 percent of Muslims vs. 28 percent of the general public.)

Contrast that with the economic situation of France’s Muslims, who suffer from a lack of education and employment opportunities. While data based on religious identity can be hard to come by in France because of the country’s prohibition on collecting data on its citizens’ race or religion, France’s national statistical agency found that in 2013, the unemployment rate for all immigrants was at 17.3 percent, almost double the nonimmigrant rate of 9.7 percent. A Stanford study concluded that a Christian citizen in France is two-and-a-half times more likely than a Muslim citizen with the same qualifications to get called for a job interview.

“Our data found that Muslims in the U.S. are employed and educated at very similar levels to the general population,” says Alan Cooperman, director of religion research at Pew. “In Western Europe, Muslims tend to lag the overall population in socioeconomic status.”

Part of that lag can be attributed to the types of Muslim immigrants that have settled in the U.S. versus those who've settled in Europe. Many Muslims came to the United States after the Imigration Act of 1965, and included highly skilled and educated workers. The Muslims migrating to Europe, however, have tended to be economic migrants who labored in factories or came as guest workers.

But even the working class Muslim immigrants in the United States have hope for the future and a belief in upward mobility -- a sense that doesn’t exist among French Muslims.

“If you look at the same demographic in America, the cab drivers, store workers seem to have more hope in economic mobility in the U.S. than the do in Europe. In America, maybe the parents come as laborers, but their kids go up the ladder. There’s some upward mobility,” says Amanullah. “In Europe, the feeling is often that ‘my fate is the same as my parents’ fate.’ That’s where the frustration sets in.”

Muslims listen during a press conference at the mosque of Luce, near Chartres, France. JEAN-FRANCOIS MONIER/AFP/Getty Images

Pluralism Breeds Integration

Experts say the ethos of American society -- which favors pluralism but does not squash individual identity or religion -- is also conducive to integration. France, on the other hand, prizes the concept of laïcité, or a strict sense of secularism that aims to keep religion out of public life. It’s that principle that has led France to ban French schoolgirls from wearing the headscarf in school, for example, that often makes French Muslims feel as though they must give up their Muslim identity to assume a French one.

“Unity in France is achieved at the expense of the affirmation of differences. As long as French does not solve its larger identity crisis, religious minorities -- especially Muslims -- will always be seen as a threat to French unity,” says Rim-Sarah Alouane, a Ph.D. candidate at the University of Toulouse who studies French Muslim youth and religious freedom.

Ahmed agrees. “If you talk to French Muslims, they’ll tell you they want to be loyal, good citizens of France and good Muslims. They don’t see this as incompatible,” he says. But French society is sending a different message to these young Muslims -- many of whom are born and raised in France.

“A French female activist of North African descent said this to me when I was studying the Muslim population there: ‘For us, France is like a mother, and we feel that the mother has pushed us away. She doesn’t love us,’” he says. “When your mother is cruel and rejects you, you feel anger, frustration. You want to do something in revenge.”