After costly U.S. engagement in two major wars in the Middle East, our foreign policy debates are dominated by questions about the appropriateness of American military interventions. A central issue is whether an interventionist foreign policy is compatible with the American constitutional tradition and the temperament that this tradition requires. Irving Babbitt (1865-1933) explored this question in depth. By linking foreign policy to questions of the soul, he explored how a nation's "body of moral habits and beliefs" would ultimately shape its foreign policy. Babbitt felt that the substitution of expansive, sentimental Romanticism for the religious and ethical traditions of the West would lead to imperialism. Research for this dissertation involved a thorough review of Babbitt's writings, including articles and lecture notes never published in books. (Babbitt's papers are available at Harvard University.) Particular attention was given to his most famous and relevant books, Democracy and Leadership and Rousseau and Romanticism although a number of obscure essays and letters have been cited. The dissertation points to the unique contribution made by Irving Babbitt to understanding the quality of foreign policy leadership in a democracy. Babbitt explored how a democratic nation's foreign policy is a product of the moral and cultural tendencies of the nation's leaders. Democracies that lack political restraint and tend toward plebiscitary practices and outcomes are more likely to be warlike and imperialistic. The United States has been moving!away from the restraining order of sound constitutionalism and, with that departure, has shown an increasing tendency to try to impose its will on other nations. In the contemporary global environment, this interventionism will inevitably cause the United States to clash with the "civilizational" regions that have emerged in recent decades. As described by Harvard historian Samuel Huntington, the tendency of the post-Cold War world order has been a realignment based upon historical, religious and cultural traditions. In Babbitt's time, the most pressing foreign policy challenge was nationalism in Europe; the current U.S. challenge is to avoid cultural and military imperialism at a time when civilizational regions are returning to their historical roots. How to address the problem of tension between civilizations is a subject to which Babbitt, showing characteristic foresight, devoted much attention.