On 26 March 2013, former Dean of the Harvard Kennedy School Joseph S. Nye led a seminar on presidents and the creation of the American era at Georgetown University's Mortara Center for International Studies. Professor Nye discussed about to what extent leadership mattered in establishing the United States as the dominant country in the twentieth century, and what lessons can be drawn for leadership and U.S. foreign policy in the twenty-first century. The Journal sat down with Professor Nye after the event to hear more about his views on the role of leadership in shaping and promoting U.S. foreign policy.