Chemical weapons are still a viable military option. This book assesses their appeal by examining how the agents, munitions and protective equipment of chemical warfare have evolved since 1915, how technological innovations and refinements in weaponry have altered tactical assumptions, and how these weapons have been employed in conflicts from the First World War to the Gulf War. The author argues that the weapon technology has proved inherently dynamic, that a new generation of biochemical agents may soon be available, and that arms control may not be able to curb these developments.