Buyer beware: “Nuclear Decisions: Changing the Course of Nuclear Weapons Programs” is not for the general reader but for the many wonks among us fascinated by a world graced with nine nuclear-armed nations. We ask: why nine, so many? Why not many more? Academics keep pumping out books with different theories but most are hardly entertaining. Nuclear Decisions does entertain, as long as your idea of entertainment is a careful exploration of the notion that proliferation decisions cannot be explained by a given country’s security environment, but rather that such decisions are made by human leaders buffeted by domestic and international concerns. In necessarily becoming rather detailed and technical, the author distinguishes Nuclear Decisions with a style as clear as a bell and with a smooth grasp of plotting. The nine country case studies taken from what she sees as the three nonproliferation eras (permissive, transition, nonproliferation regime, in itself a useful concept) are fascinating. All in all, Nuclear Decisions is a dazzling treat for those ordinary people like us puzzling about the nuclear threat.