In Religion and the Struggle for European Union, Brent F. Nelsen and James L. Guth delve into the powerful role of religion in shaping European attitudes on politics, political integration, and the national and continental identities of its leaders and citizens. Nelsen and Guth contend that for centuries Catholicism promoted the universality of the Church and the essential unity of Christendom. Protestantism, by contrast, esteemed particularity and feared Catholic dominance. These differing visions of Europe have influenced the process of postwar integration in profound ways. Nelsen and Guth compare the Catholic view of Europe as a single cultural entity best governed as a unified polity against traditional Protestant estrangement from continental culture and its preference for pragmatic cooperation over the sacrifice of sovereignty. As the authors show, this deep cultural divide, rooted in the struggles of the Reformation, resists the ongoing secularization of the continent. Unless addressed, it threatens decades of hard-won gains in security and prosperity. Farsighted and rich with data, Religion and the Struggle for European Union offers a pragmatic way forward in the EU’s attempts to solve its social, economic, and political crises.