Diplomatic machinations to limit Iranian and North Korean nuclear pro­grams command headlines. To make sense of why nuclear programs in these countries have proved to be so difficult to restrain, one could not do better than consult Grégoire Mallard’s thoughtful, analytic history of global nuclear di­plomacy. Fallout’s strength lies in its ability to combine historical detail with conceptual clarity in order to bring diplomatic choices into focus. The book portrays law not just as something made by men and women in robes but also as a phenomenon that is constructed by how people talk about and use written laws and unwritten norms.

Mallard proposes a typology of interpretive maneuvers regarding the law: transparency, ambiguity, and opacity. A casual reader might think that these three concepts mean more or less the same thing or that all international laws are ambiguous. Mallard argues that the world is not so simple. He shows how diplomats can choose among these three approaches. Furthermore, there are reasons rooted in domestic politics why diplomats might favor transparency and opacity in law over ambiguity. Mallard defines opacity as the idea that there “should be at least two truths, one for insiders and one for outsiders” (p. 25). Opacity is the realm of secret meetings and backroom deals.

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