This article reviews the potential for United States accession to the United Nations Convention on the Law of the Sea (UNCLOS) under the current U.S. leadership, the administration of President Donald J. Trump and the Republican-controlled Congress. The strategic significance of U.S. ratification of UNCLOS is demonstrated by U.S. claims and rights in areas subject to geopolitical contestation such as the Arctic and South China Sea. More broadly, the United States has a compelling interest in preserving the international order and protecting the global commons, as embodied in the terms of the treaty. Despite clear evidence that ratification is in the U.S. national interest, UNCLOS faces the obstacle of continued Senate inaction and the challenge of a domestic political atmosphere suspicious of international law and institutions. President Trump, as a Republican leader and populist dealmaker, may be well-positioned to overcome domestic political opposition and achieve a vital U.S. foreign policy objective that has eluded his White House predecessors.