In 2014, John P. Caves, Jr., and W. Seth Carus of the Center for the Study of Weapons of Mass Destruction at National Defense University published a paper on the future of weapons of mass destruction (WMD). That paper projected WMD-relevant geopolitical and technological trends and made judgments as to how those trends would shape the nature and role of WMD in 2030. Significant geopolitical and technological developments bearing on the future of WMD have emerged since the 2014 paper or were largely not addressed in that study. This paper, which was finalized in early November 2020, assesses and offers policy considerations on six baskets of such developments. They include 1) the shifting roles of the great powers; 2) new pressures on arms control and nonproliferation regimes; 3) more roles for chemical and biological weapons; 4) expanding use of financial sanctions as an instrument of nonproliferation and other policies; 5) new types of delivery vehicles and more scope to develop and deploy them; and 6) other emerging and disruptive technologies with WMD relevance including artificial intelligence, biotechnology, quantum systems, and additive manufacturing.