How important are foreign affairs in the grand scheme of civilization? Do defenses against the invasion of strangers influence the evolution of culture? Drawing on decades of experience in government as well as in the academy, William R. Polk offers a uniquely informed, comprehensive view of foreign relations. Bridging academic disciplines he treats foreign affairs as they occur in the real world. Instead of separating diplomacy, intelligence and espionage, defense and warfare, trade and aid, intervention and law from one another, he shows how they interact and together form a whole pattern with which we must deal if we are to move safely into the 21st century. But Neighbors and Strangers is not just a guide to the future; Polk draws upon all recorded history, and indeed upon studies of animal and primitive social behavior, and from the entire world for vivid examples to illuminate for the general reader the underlying principles and consistencies that characterize relations with foreigners. Indeed, going deeper into the human experience, Polk documents "fear of the foreigner" as a visceral response so deep-seated and so pervasive that it transcends human memory, individual experience and even logical analysis. More generally, he shows that the tension created by having to live as neighbors with those who, in the definition of contemporaries, were irredeemably alien has been one of the major causes of the rise of civilizations. Accessible and engaging, Neighbors and Strangers is a revelatory look at how foreign affairs are a profound reflection of human nature.