During World War I, teams of chemists, engineers, and military leaders in Germany, France, the United States and elsewhere worked to prepare chemical weapons that could be deployed on battlefields. The field use of chemical weapons proved to be difficult and unreliable so they were little used as combat weapons in World War II, though related chemicals were key tools of the Nazi holocaust. Chemical weapons have also been deployed often in smaller conflicts, including very recently. If the first world war was the chemists? war, the second was the physicists' and led to the development and use of nuclear weapons. Fortunately, there has not yet been a biologists? war, although germ warfare has been an active area of research by national governments. In the period after World War II, international efforts at controlling weapons of mass destruction, preventing their proliferation to other nations, and protecting stockpiles from falling into unauthorized hands has proved to be difficult and complicated. In this course students become familiar with the history of weapons of mass destruction and analyze humanitarian, political, and geopolitical arguments about their development and possible use. Students also learn to evaluate strategies for their control.