This paper offers the first systematic analysis of the linkage between cultural worldviews, partisanship, and the making of U.S. foreign policy. Although partisan disagreement over foreign policy reflects the interplay of complex causes, ideological and cultural divergence has been at a minimum salient and at a maximum determinative of foreign policy differences in the post-Cold War era. Since the Cold War ended, America's political parties have demonstrated foreign policy preferences that differ in consistent and coherent ways that correspond to the distinctive cultural worldviews that underlie and differentiate them from each other. Embedded in this observation are three supporting claims that this study synthesizes and supports through a systematic overview of foreign policy "key votes" taken from the Congressional Quarterly Almanac between 1989 and 2004. First, partisanship exerts a discernible influence in foreign-policymaking. That is, the parties will choose different policy options under the same circumstances in at least some cases and do so in consistent ways. Second, the parties can be differentiated from each other by reference to their underlying cultural worldviews in a manner consistent with expectations identified in recent studies of partisan polarization. In other words, the parties look at the world from distinct cultural perspectives that yield different value judgments and policy preferences, including in the foreign policy realm. Third, cultural worldviews matter to the conceptualization of U.S. foreign policy and the definition of the national interest. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]