An indispensable introduction to this timely topic. Nationalism is one of the most pressing of global problems, exacerbating ethnic conflicts and increasing the likelihood of war. It is also basic to defining the rights of democratic citizenship, and can be a source of inspiration and social solidarity. In this fascinating overview, Craig Calhoun considers nationalism’s diverse manifestations, its history, and its relationship to imperialism and colonialism. A way of conceiving identities that is fundamental to the modern world, nationalism is distinct from kinship and ethnicity. It is an international discourse that shapes domestic politics and relations between states. Drawing on examples ranging from Eritrea, the former Yugoslavia, and China to France and Germany, Calhoun clarifies the ways national boundaries and identities have become central to the modern era, how they relate to the development of state power, and how a host of social movements and government policy makers try to make use of them. Calhoun also challenges attempts to “debunk” nationalism that fail to grasp why it has such power and centrality in modern life.