Sultan Knish a blog by Daniel Greenfield:

As Americans are blinded to the dangers of Islam by their experience with multiculturalism, Europeans are blinded to the dangers of Islam by their inexperience with multiculturalism. Both make the mistake of assuming that Islamic violence is part of the multicultural norm, rather than the resumption of an old invasion of Europe. The chaos and confusion in a multicultural society can make it hard to spot real threats against the background noise, frustrations and raw nerves of cultural friction. It becomes easy to lump in complaints about too many Indian restaurants, with complaints about angry mosque worshipers. And it becomes all too easy for authorities to tell people to just make the best of it, while ignoring the situation. The authorities are certain that eventually a natural balance will arise a generation or two down the road. The slow realization that the native born Muslims are actually more radicalized than their fathers and grandfathers is worrying them, but not in a particularly constructive way. Instead they are torn between England's accommodation policies and France's integration policies, neither of which get at the heart of the problem.

Debates over swimming classes or a radical mosque here and there are only the smaller branches of a fast growing tree. Because the problem is not merely cultural differences, those can be and have been accommodated. The problem is that Muslims believe that their way of life is morally superior, and that any system or institution that does not follow those laws, is invalid. Furthermore they believe that they have a duty to impose their laws on others in the name of their religion or honor.

Right on target. I don't know what proportion or what is the number of Muslims who actually believe that, but certainly there is an important number who consider that they are morally superior.