In honor of the 100th birthday of Hans Joachim Morgenthau, the godfather of realism, a group of distinguished academics and practitioners gathered in Munich to discuss his legacy and impact on international politics today. This comprehensive volume documents the academic exercise and presents a critical appraisal of realism and its unbroken usefulness for understanding the dynamics of today's international order. What are the intellectual roots of Morgenthau's realism? What are the lessons policy-makers can draw from Morgenthau's approach? Is Morgenthau's theory an operative tool to overcome the challenges in transatlantic relations? These and further central questions culminate in a conclusive and compelling case study of the American-led war in Iraq.