Two things really struck us while working on this story. First, we're in the middle of the biggest population shift in more than 1000 years, as Muslim populations grow steadily in countries like Britain, France and yes, Australia. Secondly, the London bombers were home grown, seemingly ordinary Englishmen. Now, there's do doubt the vast majority of Muslims just want a peaceful life. But some don't. That's where the danger may lie. And that's why we've been into the suburbs of Paris and Amsterdam, Sydney and Melbourne listening to Muslims, seeing what they hold dear.
SHEIKH KHALID YASIN: Our message is to young people, young brothers and sisters trust is sacred, and how can you put a sacred trust in the hands of a non-Muslim that doesn't understand what that sanctity is about?
PETER OVERTON: My journey into the world of Islam began here a suburban town hall in Sydney.
SHEIKH KHALID YASIN: I like to talk like one of you.
PETER OVERTON: These are young Muslims and they're Australian. Most of them were born here. But the message they were hearing was of a world that sounds so alien to so many of us.
SHEIKH KHALID YASIN: There's no such thing as a Muslim having a non-Muslim friend, so a non-Muslim could be your associate but they can't be a friend. They're not your friend because they don't understand your religious principles and they cannot because they don't understand your faith. PETER OVERTON: Sheikh Khalid Yasin is not an enemy of the Western world but nor is he a friend. For him, Muslims and non-Muslims will be forever divided.
SHEIKH KHALID YASIN: Australians have to wake up and smell the coffee. To what extent do people expect that people assimilate to where it gets to the point where you actually want me to imitate?
PETER OVERTON: Khalid was born in America and was once a patriot. He served in Vietnam, but then converted to Islam. Now he's a true believer in the Koran, an uncompromising disciple of its strict justice system, travelling the world to spread his message. This is what he believes men should do to wives who disobey.
SHEIKH KHALID YASIN: The verse says (speaks Arabic). Specifically, this means, if you take that word literally, it means literally beat them lightly, like I would my child. Like that or like that.
PETER OVERTON: These are the kind of messages that drive a wedge, pushing Muslims and non-Muslims further apart at a time when relations are already strained, but we're in the midst of the greatest shift in global population since the eighth century. Muslims are building large and growing minorities across the Western world. How we deal with this here in Australia will determine the kind of country we become. Do you see Australia having Muslim/Islam as the dominant religion here one day?
SHEIKH MOHAMMAD OMRAN: Why not? What's wrong with that?
PETER OVERTON: There are now nearly 500,000 Muslims living in Australia. Sheikh Mohammad Omran is a prominent member of that community, a Melbourne-based Muslim leader.
SHEIKH MOHAMMAD OMRAN: We choose to come to Australia as Australia welcomed us to come. You didn't choose to come to Australia anyhow. And we believe we have more rights than you because we choose Australia to be our country and you didn't. So don't come to me now because you are the majority or you are in the power now to say to me, "Well, this is only my way or the highway". I won't accept that.
PETER OVERTON: Sheikh Omran represents the most fundamental of all Islamic groups in Australia. They see themselves as the true believers, defenders of the Koran against the Western world.
SHEIKH MOHAMMAD OMRAN: You destroyed Iraq altogether. You say, "We want to build a democracy." Where is the democracy? No democracy. You condemned 50 killed in Britain, fair enough. But every day, more than 100 killed in Iraq. This is right and this is wrong?
PETER OVERTON: To truly understand the growing influence of Islam on the Western world, we travelled to Europe where Muslim immigration has been under way for 40 years. Here, by mid-century, one in five Europeans will be Muslim, and, in Holland, multiculturalism has soured under the pressure. This is a place where prostitutes pay income tax and I can get cannabis with my coffee. The Dutch embrace same-sex marriage and euthanasia, yet the fabric of Holland is changing. Within a decade, its three major cities, including Amsterdam, could be majority Muslim and this most tolerant of countries is responding by passing radically intolerant laws.
FILM: I feel at least once a week the strength of my husband's fist on my face.
PETER OVERTON: Dutch film-maker Theo van Gogh made a controversial movie about violence against women in Islamic societies. In November last year, in broad daylight on a busy Amsterdam street, he was murdered by a young Muslim extremist. Shot several times, his throat slit and a message of hate pinned to his chest with a knife. The Dutch reacted angrily, public opinion was galvanised. The government approved tough new immigration laws, including a requirement that you must learn the language to come.
GEERT WILDERS: It's not a racism or whatever to say that we should prevail this culture and if people come from other cultures, they are welcome here, but they should live according to our culture and according to our laws.
PETER OVERTON: So the house-full sign goes up on anyone who isn't a Westerner?
GEERT WILDERS: They were pampered in Holland from the day they came to Holland and it was unacceptable and politically incorrect to tell them that those are our rules and if you don't like them you can leave through that door, and if you don't go voluntarily, we will help you.
PETER OVERTON: Geert Wilders is a Dutch politician whose life is under threat. Following van Gogh's murder, he called for a ban on all Muslim immigration to Holland and that has made him a target for extremists.
GEERT WILDERS: It's not a problem of a lack of integration, it's a problem of hate of everything that we stand for.
PETER OVERTON: You've been accused of being an enemy of Islam and should be beheaded are you an enemy of Islam?
GEERT WILDERS: No, I'm not an enemy of Islam. I don't hate Islam. I believe that Islam is not compatible with democracy. This is true.
PETER OVERTON: That famed Dutch tolerance turned to violence and vengeance against Muslims. Forty percent of the population say they hope Muslims no longer feel at home in Holland.
DRIESELL BEZUHLY: This is a real problem. I spent the first 20 years of my life in Morocco. But my children were born and raised here, and, if the majority of the Dutch decide that we are not welcomed here, then it's going to be a problem for them.
PETER OVERTON: Driesell Bezuhly came to Holland 40 years ago from Morocco. But he and his family have felt the changes sweeping the land in the wake of anti-Muslim sentiment.
BEZUHLY (DAUGHTER): I don't think I feel Dutch. I am Dutch, because I was born here, and there is no ... there is no other thing I could be. My parents are from Morocco, but I am born here, so I'm Dutch.
PETER OVERTON: From Holland to France. Five million Muslims live here the largest Islamic community in Europe, and here, too, a backlash is under way. This is the Paris of 2005. And so is this. Dish City so-called because of the satellite dishes picking up Moroccan TV, an entire neighbourhood occupied by Muslim families and off limits to anyone else. These housing commission suburbs on the outskirts of Paris are virtual no-go zones for anyone who doesn't live here. They are places where serious crime is rife, gang rapes are not uncommon and it's feared they are breeding grounds for extremists. We've been told we are putting ourselves at risk by coming here and I must say I don't feel very comfortable at all. Here, too, legislation has been toughened. In an effort to defend France's secular culture, Muslim girls have been forbidden to wear the traditional head scarf to public schools. For girls like Zanib, born and bred in Paris, it was an attack on her identity.
ZANIB: To me, it's my faith, it's my spirit, it's who I am, and those people say that I don't want to be integrated, well, how can you talk about integration when I am from here? How do I integrate to a place that is already, is already me?
PETER OVERTON: Back home, we pride ourselves on being a truly multicultural nation. But we're not immune to the growing resentment many Muslim communities overseas are facing.
NEIL FERGUS: There has to be a more sane approach to this in fundamentalist Islamic circles. The reality is in mainstream Islamic circles, this is regarded as lunacy.
PETER OVERTON: Terrorism expert Neil Fergus believes Muslim leaders hold the key to heading young Muslims in the right direction.
NEIL FERGUS: There isn't room for leading imams to sit on the fence any more. They really need to be forthright and show some leadership and some moral fibre in terms of giving their followers a clear direction on how these type of abhorrent events sit against the word of the prophet.
PETER OVERTON: Who is responsible for September 11?
SHEIKH MOHAMMAD OMRAN: I don't want to say USA Government, but I would say some of them, they are responsible for that.
PETER OVERTON: The Government is responsible?
SHEIKH MOHAMMAD OMRAN: Yes. Yes! I believe in that 100 percent. I believe there is what they call it? A conspiracy against Islam and Muslims.
PETER OVERTON: I think the average person out there would be amazed that you don't think Osama bin Laden was responsible for September 11.
SHEIKH MOHAMMAD OMRAN: There is a mastermind behind these things and the mastermind 100 percent he is from the US Government.
DANNY NALIA: No Muslim can deny the fact that Islam calls on the whole world to be Islamic.
PETER OVERTON: Christian pastor Danny Nalia is unashamedly critical of the Muslim teachings that divide communities. A lecture he gave to his Melbourne congregation was found to vilify Muslims and he's been ordered to apologise or risk jail.
DANNY NALIA: We have just sacrificed freedom of speech and democracy for Islamic Sharia law by stealth.
PETER OVERTON: Will you apologise? You've been found guilty of vilifying Muslims.
DANNY NALIA: We will not apologise and we stand by what we said. If it means going to jail, yes, we shall go to jail. There was a website article in the recent past where one of the Islamic groups in Victoria or NSW which stated that Muslims are like water coming out of a pure water spring and that all non-Muslims were like water coming out of a suburban sewer and they called on all Muslims not to assimilate into Australian society, because if a drop of suburban sewer falls into the pure water spring, it will pollute the water.
SHEIKH KHALID YASIN: A Muslim needs to distinguish him and herself.
PETER OVERTON: That's certainly the kind of message Sheikh Khalid Yasin was preaching at Bankstown Town Hall 10 days after the London terrorist bombings this from a man who was about to apply to become an Australian resident.
SHEIKH KHALID YASIN: If you prefer the name of somebody on your clothes other than the name of the Muslims, if you prefer the clothing of the Kaffers other than the clothing of the Muslims, most of the names that's on most of those clothing is faggots, homosexuals and lesbians. God is very straightforward about this not we Muslims, not subjective, the Sharia is very clear about it, the punishment for homosexuality, bestiality or anything like that is death. We don't make any excuses about that, it's not our law it's the Koran.
PETER OVERTON: And this on why young Muslims shouldn't attend university.
SHEIKH KHALID YASIN: The university is a gateway for deviation. You forget your Islamic direction. Now you have become compromised through some kind of intellectuality.
PETER OVERTON: Some of the things I've seen and heard around the world these last weeks are really difficult to accept beliefs so foreign to our own way of life. But, with the biggest Islamic nation in the world as our next door neighbour and 500,000 Muslims in Australia, we just have to find a way to get along.
PETER OVERTON: Can Australians and Muslims live together?
SHEIKH MOHAMMAD OMRAN: One hundred percent. They are living together, my dear, where are you now? You are in my mosque and you are living with me and there is millions of people here around me, most of them non-Muslims. So why we don't?
PETER OVERTON: But there are differences in beliefs.
SHEIKH MOHAMMAD OMRAN: So what? We agreed to build an Australian nation, a strong nation, a harmony nation, but with so many differences among us, so what?