The major purpose of this book is to examine Christian Realism as articulated by Reinhold Niebuhr and to see whether his theory can shed any light on world politics especially in a nuclear age. Major themes of Niebuhr's theory included in this book are: Niebuhr's understanding of human nature, critique of idealism and naturalism and the dialecticalexistential framework. Niebuhr's thoughts on love, justice, power, society, community and responsibility, as well as his thought on world politics are discussed. This book also covers Niebuhr's understanding of national interests, balance of power, imperialism, democracy and the developing countries. Niebuhr's Just War theory is compared with many other major thinkers on the subject. Niebuhr's Just War theory in a nuclear and terror age was examined with particular interest. Topics include: Terror, Counter-Terror and the Just War theory, Jihad, Nuclear Terrorism, Pre-emptive strike against nuclear facilities and the Just War theory. Niebuhr's approaches to peace in a nuclear and terror age are also discussed. One of the major challenges to U.S. foreign policy today is North Korea's nuclear proliferation. This book attempts to provide a theoretical guideline for U.S. policy vis- -vis North Korea's nuke. John Hoyoung Lee is the former professor of church history at Westminster Theological Seminary in Philadelphia and emeritus professor of economics and political science at the Rochester Institute of Technology. Dr. Lee was also the senior pastor of the Bethel Korean Presbyterian Church in Ellicott City, MD.