In this unprecedented, monumental work--at once panoramic and rich with detail--Andrew Preston examines the role of religion in American foreign policy from the earliest days through the end of the Cold War, revealing the influence religion has had on the way Americans and our leaders have understood our place in the world. Without arguing for or against any religion, Preston makes clear how faith, both public and personal, has figured into our foreign relations, from the question of slavery to the debate over imperialism in the Philippines after the Spanish-American War, from America's involvement in World War I to Harry Truman's Cold War doctrine of containment. This is a boldly original synthesis of American history, a hugely ambitious book that fully acknowledges the complexities of history as it illuminates the ways in which Americans have balanced the intractable tensions between pragmatic self-interest and the idealistic demands of faith.