"History repeats itself, but it never repeats itself exactly," observes Douglas Porpora in this powerful indictment of U.S. intervention in Central America. Comparing the general public’s reaction to the Holocaust in Nazi Germany with American public opinion of U.S. participation in the genocidal policies of Nicaraguan counter-revolutionary forces, and the governments of Guatemala and El Salvador among others, Porpora demonstrates that moral indifference to the suffering of others was the common response. With reference to Hannah Arendt’s thesis of the banality of evil, he develops the concept of a "Holocaust-like event" and examines how even a democratic society can be capable of something on the order of a Holocaust.

Unlike other accounts of the Holocaust and genocide, this book focuses on the citizenry served or ruled by genocidal governments rather than on the governments themselves. Porpora argues that moral indifference and lack of interest in critical reflection are key factors that enable Holocaust-like events to happen And he characterizes American society as being typically indifferent to the fate of other people, uninformed, and anti-intellectual.

Porpora cites numerous horrifying examples of U.S.-backed Latin American government actions against their own peasants, Indians, and dissident factions. He offers finally a theory of public moral indifference and argues that although such indifference is socially created by government, the media, churches, and other institutions, we, the public, must ultimately take responsibility for it. How Holocausts Happen is at once a scholarly examination of the nature of genocide and a stinging indictment of American society.