Chemical weapons, banned under the Geneva Conventions, are the subject of revulsion and contempt to fighting men. Yet as Weapons of Mass Destruction no country with significant military capacity is able to afford to ignore them. They became, after an initial period of use during the Great War, weapons of deterrent. Despite the apparent military misgivings, much public hysteria about the horrors of chemical warfare was whipped-up by the media throughout the inter-war years. The book looks at the way in which this hysteria was manipulated and channelled by the British Government to ensure the establishment of a powerful and effective civilian anti-gas air raids precaution mentality which was then insidiously refocused upon the real threat, which was from high explosives and incendiary bombs. A major chapter is devoted to the use of chemical weapons in WW1, which was seldom successful and often counter-productive being indiscriminate in their effect. Another chapter covers the Italian use of CW in Ethiopia and by the Japanese against Chinese troops and civilians in the Sino-Japanese War. The latter part of the book examines the way in which the chemical warfare initiative moved away from the domination of the chemical industry into the control of the intelligence services through the Cold War years. Paranoia, and the irrational assumption that whatever weapons one side had then the other must have developed something even more frightening, led to the accumulation of vast deterrent stockpiles of weapons ' mainly nerve gas projectiles. By the early 1990s the magnitude of these stockpiles frightened governments into a programme of mutual stock reduction and destruction, which has led to a potential environmental disaster.