This book tells how a group of Protestant theologians forged a theology of international engagement for America in the 1930s and 40s, and how in doing so they informed the public rationale for the United States' participation in World War II and stimulated American leadership in establishing both secular and international organizations for the promotion of world order. This remarkable group included Henry P. Van Dusen, Reinhold Niebuhr, John Bennett, Francis P. Miller, Georgia Harkness, and Samual McCrea Cavert. Warren show how, in creating a coherent, theologically-derived position and bringing it to bear on contemporary international issues, this group combined ideas with public action in a way that set the standard for American theologians' social activism in the years to come.