Jim talks with historian Richard Overy about his new book Why War? They discuss historians' shyness in thinking about the nature of war, a correspondence between Einstein & Freud, the meaning of the term, the "pacified past," the interplay between warfare & cooperation, recent ethological studies of chimpanzees, conformity, 4 major types of anthropological evidence, the status of warriors over time, ecological drivers of war, Marxian analyses of war, hubristic warfare, Rome's centuries of warfare, the illusion of security, the future of war, and much more.