Milan, Italy - A failure of integration? - In the third and final part of his series about young Muslims in Europe, Roger Hardy visits a reputed hub of Islamic radicalism.
In a courtroom in Milan, packed with armed police, a metal cage holds six young Muslim defendants.
They are accused of sending militants to fight in Iraq and plotting a bomb attack which Italian police managed to nip in the bud.
During a break in proceedings, I ask veteran prosecutor Armando Spataro if he sees a clear link between integration and security.
"Terrorist groups refuse integration," he says.
Accordingly, integrating Europe's Muslims is a way of strengthening the moderates - and a necessary part of winning the "war on terror".
That metal cage serves as a warning of where Italy - and Europe - could be heading.
Italian officials have known for some time their country was exporting Islamic militants. Now they worry that militants may return from fighting in Iraq to carry out bombings in Europe.
Italy is distinct from the countries I visited in northern Europe. Muslims have arrived here more recently and relatively few have acquired citizenship.
"It's a community without integration," says Magdi Allam, well-known Egyptian-born columnist at the Corriere della Sera newspaper.
"The majority of Muslims in Italy don't speak Italian in a proper way, don't know the culture or the religion of the Italian people, and don't share the values of Italian society."
He is deeply suspicious of mosques which have fallen under the sway of radical imams.
Anger over cartoons
I go to watch Friday prayers at the Islamic Cultural Centre, Milan's most infamous mosque - situated incongruously behind a car wash.
The controversy over cartoons depicting the Prophet Muhammad is in full flood.
The mosque's Egyptian imam, Abu Imad, mocks the "ignorant people" who published them.
"Who are these people?" he asks ironically. "Do they think that if they blow hard enough they can put out the sun?"
When I interview him, Abu Imad denies that he has links with radical groups outside the country - or that he sends young men to blow themselves up in Iraq.
Opposing views
The cartoon affair - and the wave of protest it unleashed - is the latest crisis to drive a wedge between Muslims and non-Muslims in Europe.
It has encouraged both sides to believe the worst of the other.
Supporters of their publication see Muslims as illiberal and prone to violence.
Opponents regard the newspaper editors as guilty of an affront - even a calculated affront - to Muslims and to the essence of what Muslims believe.
Magdi Allam supports his newspaper's decision to republish the cartoons.
The West should hold fast to its values, he tells me, and Muslims who want to live in the West must accept those values.
More typical of Muslim opinion is the view that the cartoons are an insult.
"They eat our hearts," says Usama, a 20-year-old student at Milan University.
My European journey took me from Leeds and Paris to Amsterdam and finally Milan.
There are many ways of being a young Muslim in the new Europe.
Many embrace a vibrant youth culture, while Islam - if it matters at all - is simply a badge of identity.
Others are finding a new identity based on an Islam very different from that of their parents.
The idea that integration is not taking place at all - and that Islam just will not fit into European society - seems to me a myth.
But integration is a slow and difficult process. No one country can claim to have got it right.
Whatever the rights and wrongs of the cartoon affair, it has increased the sense of polarisation and may have set back the prospects for integration.
And if integration fails, Europe's security as well as its social harmony will be jeopardised.