"Technology fuels the arms race" is one of the unexamined maxims of foreign affairs. This interesting book is an effort at remedy. Drawing on a major case study of tactical nuclear weapons, it seeks to understand the pressures for innovation that derive both from within and outside the two superpowers. It concludes that in the United States "the impetus for innovation in weapons technology comes from the bottom," while in the Soviet Union, given secrecy and rigidity, it is more likely to come from the top; thus, the U.S. introduces, the Soviet Union reproduces, in quantity. The resulting policy prescription-U.S. technological restraint traded for Soviet quantitative limits-is not new, but the analysis makes it more interesting.