The author tries to set ethnic cleansing and genocide in relation to both psychoanalytic understanding of the human mind and of groups, and to certain aspects of modern society and modernism. Following the Polish sociologist Zygmund Bauman, he claims that genocidal situations can be a product of certain properties of modern society which under certain situations (i.e., under totalitarian conditions) can come into being. Malignant group processes can then cause more-or-less organized cruel acts. The worst example is the Holocaust during the second world war, but the problem has seen new, sad repetition in recent years (i.e., Bosnia Herzegovina). Psychoanalysis can shed light on and partly explain how individuals and groups under these circumstances can change and then execute cruel acts, often on a mass-scale. The importance of prevention is stressed. An aspect of this is the afterwork (including the work of grief) after the atrocities, so as to prevent the next generations continuing the cruelties.