James Lileks nails it (thanks to Doc Washburn for the link).
If you mock Islam with a drawing or a novel, you get riots and dead people. News of mishandled holy books yields riots and dead people. Insufficiently reverent short films by a Dutchman yields a dead person, specifically the Dutchman.
Now we add this detail: Quoting medieval religious colloquies is a reasonable justification for burning churches, shooting a nun and holding up signs demanding that the pope convert to Islam or saw off his own head. (There have been reports of carpal tunnel syndrome among radical Islam's enforcers, and they have requested we all help out.)
This is a new twist: Now history itself cannot be discussed. Since it's difficult to predict what else will enflame the devout, Islam has to be treated with unusual deference, like a 3-year-old child with anger management problems.
But it's not what we say that truly offends. It's what we are. The West's lack of interest in joining the Ummah is an affront in itself, and we broadcast our sins in High Infidelity. If you believed that the West's apostasy was an affront to God, you'd spend your leisure hours torching straw popes too.
Progressives at home and abroad seem oddly unconcerned. "Islamophobia," after all, is just a product of the BushCo junta's relentless fearmongering, and Benedict is the Nazi pope who personally swipes the condoms from people's bedroom drawers.
But it's an inconvenient truth, to coin a phrase, when the ranters show up with vibrating uvulas demanding the pope's assassination. (Would they be satisfied with a docudrama version? It would go over big at Cannes.)
Read it all. Read it again. Pass it around.