Preface In December 1997, six years after the Persian Gulf War, the Pentagon announced that it had decided to vaccinate its 2.4 million soldiers and reservists against anthrax. It seemed to be a curious move. Saddam Hussein s biological weapons program had been exposed more than two years earlier. So what had changed? Was the decision driven by a new, even more frightening danger from germ weapons? Was the Clinton administration looking for an international issue on which it could appear tough? We set out to explore for the New York Times what had motivated the decision. From the beginning, we worked as a team: a science writer with a knowledge of weapons, a veteran foreign correspondent who had tracked international terrorism, and an editor who had in- vestigated the intelligence agencies and the Pentagon. We were skep- tical, well aware of how federal agencies often inflate such dangers to justify their existence and budgets. We quickly learned that the anthrax decision was part of a much larger government effort to combat what officials believed was a growing danger from germ weapons. Over the next three years, we followed the story from Washington to Kazakhstan to Japan to Russia, eventually deciding to write this book. The issues were as complex and intellectually challenging as any we have ever examined, cutting across science, intelligence, and foreign affairs. We came to see the de-