This article examines the issue of riot control agents as it relates to the subject of chemical weapons arms control at the international level and, more specifically, implications for the United States. The article examines how the issue of riot control agents has complicated efforts for the United States to enter into and ratify chemical weapons-related arms control agreements. The article provides an overview of chemical weapons, examines the relevant arms control agreements, explores why and how riot control agents influence debates over the merits of these treaties, and explains why riot control agents remain a contentious issue in chemical weapons arms control and foreign policy in the United States.