This course will explore contemporary threats posed by the proliferation and use of chemical and biological weapons (CBW) by states and terrorist organizations. The course will cover the motivations for CBW acquisition and use by states and non-state actors, the role of norms, sanctions, and deterrence in restraining the proliferation and use of these weapons, and obstacles and opportunities for the CBW nonproliferation and disarmament regime. Topics to be addressed will include: (1) the strategic logic behind Syria’s use of chemical weapons; (2) the growing use of poison by authoritarian regimes for assassination purposes; (3) the Islamic State’s use of chemical weapons; (4) the threat posed by North Korea’s CBW; (5) the impact of advances in synthetic biology on biosecurity; and (6) the future of the CBW nonproliferation and disarmament regime. The course will conclude with a crisis simulation exercise.