On April 22, 1915, on a WW I battlefield near Ypres, two greenish-yellow clouds of chlorine gas rose from the German trenches over the Allied lines, killing 5,000 and wounding 10,000. This first use of a chemical weapon is where British journalists Harris and Paxman begin their comprehensive history of chemical and biological warfare--continuing through mustard and nerve gas, biological weapons such as anthrax bombs and crop destroyers, and mind-bending drugs such as LSD. It's an ugly history--all the more so for the cool, rational telling. Chlorine, phosgene, and mustard killed or wounded well over one million soldiers in World War I, and many of them were disabled for life. Subsequently, numerous humans (volunteers, unsuspecting innocents, prisoners, POWs) were experimented-on in shocking, grisly ways by all parties: the Nazis, Japanese, British, Americans, Russians. Although many of the stories are familiar--the suspicious ""epidemic"" of anthrax in Sverdlovsk, Siberia; the CIA's ""experiments"" with LSD--there is also much new material, especially about Britain's programs, gleaned from recently declassified documents and interviews. The authors go beyond the usual catalogue of horrors to explore, most importantly, the larger pattern of military thinking, planning, and decision-making. The development of chemical and biological weapons, at least in the West, has in each case followed a certain course. Development is initiated on purely defensive grounds (we have to know what the enemy might possess in order to defend ourselves from it); full-scale production follows (so we can respond to the enemy in kind and thus deter him); finally, serious consideration is given to using the weapon in extreme circumstances (if Hitler had invaded England, Churchill planned to ""drench the beach-heads"" in mustard). Two major conclusions emerge: development and production of any weapon, once dreamed up, is inevitable; once the weapon is produced, disarmament is extremely unlikely. The book is thus a model study of military planning and the problems of curbing high-technology weapons--as well as the preeminent source of factual information on chemical and biological warfare, specifically. In the wake of Sterling Seagrave's recent Yellow Rain and the attendant disclosures, its publication is also extra-timely.