Reflections on the future of American foreign policy following the September 11 terrorist attacks are best understood as part of a debate that has been on-going since the end of the Cold War. At the heart of this debate are questions of power and national purpose, themes that have long been at the heart of analyses of American foreign policy and are not unique to the post Cold War era. In this symposium I argue that as important as questions of power and purpose are, they constitute only two of the three essential pillars on which any analysis of American foreign policy must build. Questions about the third pillar, responsibility, have been relatively unexplored. Studies of power provide insight into the ability of the United States to act on the international stage. Studies of purpose, or national interest, provide insight into the range of goals that can be pursued or should be pursued in conducting foreign policy. Studies of responsibility direct our attention to questions of obligation, accountability, and definition of community. Only by examining all three pillars can one obtain a full picture of American foreign policy and reach judgements about its content.