Leftist betrayal.

The chief responsibility for the universal Islamization of Western countries is attributable solely to the overwhelmingly leftist — although in the best case also Bleeding Heart — political establishment of those countries. They alone were and are the ones who in the last fifty years have brought into their lands millions of Muslims who are incapable of adapting to the indigenous culture and values. They were authorized to do this by no one but themselves.

"Why No Guilt Attaches to Islam Critics for the Massacre in Oslo." By Michael Mannheimer
quoted in "Who Was Really Responsible for the Norway Massacre?" By Baron Bodissey, Gates of Vienna 8/21/11.