This study applies well-known arguments on the effect of conflict, alliances, and democracy on international trade to identify the determinants of dual-use trade. Dual-use commodities are those that can be used in weapons of mass destruction (WMD) programs or in legitimate civilian applications. This article advances a theory suggesting that governments seeking to maximize the gains from dual-use trade will promote exports to countries where there are security guarantees and restrict exports to countries where security threats exist. Eight hypotheses are tested using data on licensed dual-use exports from the United States to 128 countries between 1991 and 2001. The results indicate that democracy has a positive and significant effect on dual-use exports, while WMD acquisition or pursuit does not necessarily reduce states' access to such commodities. The results vary slightly, based on how dual-use exports are measured. In conducting the first systematic analysis on the determinants of dual-use trade, this study contributes to scholarly understanding of WMD proliferation and research at the nexus of international trade and international security. In particular, it offers important prescriptions for when states are likely to transfer technology that could be used to build WMD. It also encourages further work that disaggregates trade data to examine relationships between particular types of trade and conflict, alliances, free trade agreements, and other political variables.