"Sherlock Holmes solved a mystery by focusing on what didn't happen: a dog that didn't bark. The authors of this rigorously researched volume similarly explain why a widely expected event didn't happen--why several countries developed and tested radiological weapons but never deployed or used them, even though they are relatively cheap, easy to make, and assumed to have devastating effects. Their meticulous and highly readable analysis not only sheds light on a long-dormant mystery of the nuclear age, it also provides valuable insights into whether and under what circumstances states may again pursue radiological weapons and offers practical recommendations for mitigating the dangers of their possible future development. With evidence that interest in radiation dispersal as a weapon of war may be returning--for example, Russia's Poseidon "super torpedo"-- Death Dust is especially timely and should be read by nuclear policymakers as well as members of the general public concerned about the nuclear threat."--Robert Einhorn, Brookings Institution, former Assistant Secretary of State for Nonproliferation.