First thing is that we must understand that this extremism has been bolstered and strengthened by the actions of Tony Blair and Dubya Bush. Most people could see this coming. What has happened is that people who would've otherwise remained aloof from events, have felt compelled to support the extremists, given what has been happening (indiscriminate killings, sickening abuse of prisoners stealing of resources under a false premise). This is from a side purporting to represent progress and civility! Sorry to say, some of us are fully aware of the grotesque and intolerant side of Islam due to our recent history but for the west to come in on the plank of moral superiority and then be involved in all manner of zulm and questionable behaviour, takes the wind out of their argument. I am a teacher and most Muslim teenagers I have spoken to have expressed similar beliefs.
The other thing is that Islamic extremism has been around for a long time in the UK, and the governments here conveniently turned a blind to people going off for "jihads" until 9/11. Then they banned a list of orgs (including Sikhs ones!) in a knee jerk reaction. People from here have been going off to train and fight holy wars for decades. Apparently one thing commented on by British soldiers in Iraq is the surreal experience of encountering Muslims with British accents in conflicts.
Overall, an important fundamental root cause of recent issues is plain old White Supremiscism. I don't mean to offend anyone, but as long as Western European people and their descendants continue to feel that they have some right to dictate morals to the globe and take resources by force, we will have such problems. The west is now seen by many as a bankrupt immoral force. The banking system is in turmoil and again, a culture of greed and selfishness by investment bankers lay at its heart.
Recently Mr. Brown (UK Prime Minister) went to Chile and was told that recent economic problems have been created by western Europeans, who prior to this crisis, went around like they knew everything. It is the same type of ignorant, haughty behaviour by the same type of people, that has
led to the growth and expansion of Islamic fundamentalism. They have done more for this cause through their actions than years of preaching by mullahs ever could have. In my opinion, these people are as much the enemies of decent everyday folk as Bin Laden types are.