The past several years have been an era of relative calm in U.S.-South Korean trade and economic relations. The Trump administration, however, has signaled two potential paradigm shifts that could lead to greater tension in the bilateral economic relationship. The first is the president’s relatively negative view of existing U.S. trade policy and willingness to at least threaten the use of measures that historically have been infrequently deployed to correct what he views as its failures. This may affect the future course of the South Korea-U.S. Free Trade Agreement (KORUS FTA), which the administration presumably will scrutinize as part of its examination of relationships in which the United States runs a trade deficit. Second and intimately related, the president has signaled in his statements a willingness to use U.S. security relationships to influence economic relations and vice versa. On both fronts, uncertainty abounds, due in part to existing institutional structures that limit the president’s ability to take new policy directions without, for example, the consent of Congress. The administration’s own lack of clarity on its policy priorities and the possibility that stating seemingly extreme positions may represent a negotiating tactic rather than a policy shift, also cloud the outlook for how the United States will approach the bilateral economic relationship. The uncertainty also reflects the fact that key trade policy officials, including the United States Trade Representative (USTR), have yet to be confirmed.