This op/ed by Jeff Jacoby is worth reading in its entirety.
If it weren't so sickening, it would be farcical: A line in the pope's speech suggests that Islam has a dark history of violence, and offended Muslims vent their displeasure by howling for his death, firebombing churches, and attacking innocent Christians. One of the points Benedict made in his speech at the University of Regensburg was that religious faith untethered by reason can lead to savagery. The mobs denouncing him could hardly have done a better job of proving him right...
In every case, the pretext for the Muslim rage was the claim that Islam had been insulted. Freedom of speech was irrelevant: While the rioters and those inciting them routinely insult Christianity, Judaism, and other religions, they demand that no one be allowed to denigrate Islam or its prophet. It is a staggering double standard, and too many in the West seem willing to go along with it. Witness the editorials in US newspapers this week scolding the pope for his speech. Recall the State Department's condemnation of the Danish cartoons last winter.
Of course nobody's faith should be gratuitously affronted. But the real insult to Islam is not a line from a papal speech or a cartoon about Mohammed. It is the violence, terror, and bloodshed that Islamist fanatics unleash in the name of their religion -- and the unwillingness of most of the world's Muslims to say or do anything to stop them.