Bioterrorism : a complex threat / Andreas Wenger and Reto Wollenmann -- Understanding the threat : actors and capabilities -- The legacy of secret state programs / Jeanne Guillemin -- Evolution of the current threat / Milton Leitenberg -- The impact of scientific and technological change / Malcolm Dando -- Assessing the threat : differing perceptions -- Knowledge gaps and threat assessments / Peter R. Lavoy -- Why do conclusions from the experts vary? / Marie Isabelle Chevrier -- Managing the threat : policy options -- When to cry wolf, what to cry, and how to cry it / Anthony H. Cordesman -- More transparency for a secure biodefense / Iris Hunger -- Conclusion -- Securing society against the risk of bioterrorism / Andreas Wenger.