In this provocative little book, a Stanford political scientist presents an intriguing account of nationalism and its implications for conflict and cooperation. Laitin takes aim at the popular view that nationalism is dangerous, fueling a global surge in ethnic and civilizational conflict. The evidence actually reveals the opposite: most ethnic and nationalist groups live in peace with their neighbors. Drawing on a decade of work with his colleague James Fearon, Laitin details the more specific and circumstantial causes of ethnic and nationalist violence, ultimately pointing to the failure of states to enforce agreements between parties in fragmented societies. His more interesting claim is that nationalism, along with culture and language, can best be understood as a functional mechanism for social coordination rather than as a matter of primordial identity or ancient attachment. The virtue of this functionalist vision is that it helps explain the complex ways in which different national and linguistic groupings peacefully coexist within states. Laitin sees the European Union as the great showcase of how national identities can adapt to and exist alongside more encompassing multicultural identities that evolve to facilitate social cooperation. How useful this perspective is for the rest of the world is less clear.