Via a comment from this thread at Harry's Place, this essay by George Pell, Cardinal Archbishop of Sydney, Australia, is well worth a read. He summarises very well the pro- and con- views of Islam, in the West, and concludes, inter alia:
Every great nation and religion has shadows and indeed crimes in their histories. This is certainly true of Catholicism and of all Christian denominations. And it is legitimate to ask our Islamic partners in dialogue whether they believe that the peaceful suras of the Koran are abrogated by the verses of the sword. Is the program of military expansion to be resumed when possible? Do they believe that democratic majorities of Muslims in Europe would impose shari’a law? Can we discuss Islamic history and even the hermeneutical problems around the origins of the Koran without threats of violence?