War and genocide are the two principal forms of mass killing by governments; they have claimed more than 100 million lives in the twentieth century. The height of the slaughter was reached during World War II, and one legacy of that cataclysm is the continuing threat posed by tens of thousands of nuclear weapons. Through an examination of the Holocaust (the attempt to exterminate the Jewish people) and Allied strategic bombing (the attempt to exterminate German and Japanese civilians living in cities), Eric Markusen and David Kopf aim to promote understanding of and concern about what may be the most urgent present-day threat to human survival--the willingness of national governments to plan, prepare for, and carry out the extermination of masses of innocent people.Markusen and Kopf strongly disagree with scholars who regard war and genocide as separate phenomena. They find that despite important differences, there are in fact striking parallels in the psychological, organizational, and scientific-technological factors that contributed to the adoption of these programs for mass killing. The dehumanization of the victims made it psychologically easier to carry out their extermination; the preparations for slaughter within vast bureaucracies diminished the sense of individual responsibility for these lethal policies; and the rationalization of the killing was aided by intellectuals who justified their actions on the basis of allegedly scientific principles and data.The unsettling truth, according to Markusen and Kopf, is that the majority of those involved in governmental mass killings are psychologically normal and regard themselves as patriots, rather than as mass murderers. Moreover, they find that some of the same psychosocial factors that have accounted for genocide and total war also characterize the preparations of the superpowers for the possibility of future nuclear conflicts. The authors survey dangerous global trends that appear to support continued outbreaks of genocidal killing and conclude with reflections on the prospects for preventing such tragedies.