The Eleventh Plague begins with a recitation of the ten plagues brought down upon Egypt, part of the Passover Seder celebrated each spring by Jews all over the world. Spring is also the anniversary of the first use of chemical weapons. On April 22, 1915, German soldiers released chlorine gas from 5,739 cylinders installed along the battle line at Ypres in southeastern Belgium. Germany achieved complete surprise. The gas drifted across no man's land, causing widespread terror and creating ten thousand serious casualties and five thousand deaths. Chlorine, of course, was a poor weapon, easily neutralized, but German scientists, including future Nobel laureates Fritz Haber, Otto Hahn, and James Franck, and the German chemical industry created ever more dangerous chemical weapons, culminating with the introduction of mustard gas in 1917. Despite cries of moral outrage, the Allies countered with their own chemical weapons efforts. The eleventh plague had been unleashed.

Leonard Cole's purpose in writing this book is clearly stated in the introduction: "Underlying this book's recitation of facts and events is a profound human dilemma. It is the challenge of reconciling the sometimes contradictory impulses between morality and survival." The recent use of chemical weapons by Iraq, the release of sarin in the Tokyo subway by members of the Aum Shinrikyo cult, and the political controversy over the ratification of the Chemical Weapons Convention make this book especially timely. The potential use of chemical and biological weapons is a serious concern. The horrors of gas warfare during World War I created an international moral repugnance that suppressed their use for generations; but, as Cole points out, this moral barrier has been breached. The world is in increasing danger of biological and chemical attack. These weapons are cheap to build and easy to use.

In this clearly and objectively written book, Cole details the recent history of chemical and biological weapons. Part One discusses the U.S. program in chemical and biological weapons, detailing incidents where American citizens were harmed or put at risk. Part Two focuses on the Middle East: the Iran-Iraq war, and the Gulf War and its aftermath. Part Three looks at the use of chemical and biological weapons by terrorists, treaties and their enforcement, and ends with a discussion of the ethical issues surrounding these weapons.

The crucial issue for Cole and for the reader is ethics. How do we reestablish a moral barrier against the use of chemical and biological weapons? While well written and aggressively enforced treaties are important, no treaty can perfectly guard against violations by a country determined to make and use these weapons. As the recent incident in Japan illustrates, a determined terrorist organization can create havoc with a small quantity of a chemical or biological agent. Protection against such attacks is virtually impossible. The key to deterrence is ethics, not politics or technology.

Humans have long abhorred the use of poisons and disease as weapons, viewing it as inherently unfair. Healing, on the other hand, is considered a virtue. These two historic positions can help to build and maintain a moral barrier against the use of chemical and biological weapons. Cole is not a naive idealist, however. While emphasizing ethics, he also stresses the need for international agreements, enhanced intelligence and carefully controlled defense programs (with acknowledgment of their limitations).

Both students and working scientists will benefit from reading this balanced and thoughtful book. It raises important issues for us as both scientists and citizens. Cole closes his book with the thought:

The eleventh plague is entirely a human invention, a human imposition. Its avoidance is a statement of human decency, an act of will born of high principle. We can hardly afford less.