Immigration, multiculturalism and ideology
The most chilling phrase in the Norwegian horror was the killer's statement, through his lawyer, that it was "atrocious," or in another translation "gruesome," or even just that he was sorry -- but it was necessary. I've never seen anything that expresses the toxic potential of ideology so eloquently. It's especially in that note of regret. Rage and hate do terrible deeds but they may falter. An idea that you know with certainty is true can be put into action no matter what your state of mind or feelings. You might even have tears in your eyes as you shoot.