What causes one human being to kill another, not for anything the victim has done but simply because the victim belongs to a particular religion, ethnic or communal group? Such behavior confounds rationality, and analysts are forced to focus on either identifying the broad macrophenomena and the structural-cultural factors that correlate with genocide or on specifying the psychological processes that might contribute to genocide.

The most frequently cited precipitating factors or facilitating conditions that correlate with genocide and ethnic violence are political unrest and economic upheavals. The Holocaust—certainly the best known genocide—is usually "explained" by reference to the political dislocations resulting from World War I, especially the ensuing breakup of political empires, the punitive Versailles Treaty, a weak Weimar Republic, and the economic depression that gripped the world but which was particularly acute...