Mass Murder in Norway and the Spread of Multiculturalism

The death toll from last week's bombing and shootings in Norway is now said to be 76 and the names of the victims are being released. Anders Behring Breivik, who has admitted to the atrocities, is in solitary confinement and his lawyer says he's "insane," driven by the fantasy of war against Islam. In a country where the police are normally unarmed, there have been massive demonstrations of sympathy: no calls for vengeance; no security crackdown. But there's growing concern that immigration is a threat to national identity in Norway and elsewhere in Europe.  Should there be more attention to the potential excesses of right-wing reaction, not just in Europe but the US as well?