I am getting tired of the way people poke fun at Bush's stand that "They hate our freedoms". The typical argument never talks about the fundamentalists' curtailing of women's freedoms, the freedom to practise religion in any way one pleases and the freedom to pursue an education that is not mired in twelfth century dogma. Though hatred of such freedoms might not have been the reason for the terrorists to attack America, it is one of the cornerstones of their ideology, which they make use of to recruit people to their cause.
Having said this, there are also legitimate grievances that are being used by the terrorists to further their agenda (the primary one being the Israel-Palestine conflict, of course).