A brisk survey of the development of the Bomb and its immediate, Cold-War aftermath--better on the former than on the latter (and, like Clark's 1961 The Birth of the Bomb, with a distinct British emphasis). Beginning with the theoretical contributions of Einstein, Bohr, Fermi, et al., Clark distills the body of knowledge concerning nuclear fission prior to 1939. Then, though Germany began the war with the only government-sponsored nuclear research program, this edge was eroded by the braindrain of Jewish (and other) scientists, by German overconfidence following their early victories, by a weak economy and a flawed approach to nuclear power. France's 1940 collapse submerged her research assets into the British effort, while Russia's early reverses delayed her nuclear program until the 1943 victory at Stalingrad. Only Britain, Clark stresses, maintained a single-minded focus on nuclear weapons development from the start. There, the discovery by exiled German physicists Rudolf Peierls and Otto Frisch that a critical mass of uranium 235 would produce a ""chain reaction"" if bombarded by fast-neutrons, marked ""the real watershed"" in creating an atomic bomb. A vastly increased American program, the Manhattan Project, then utilized their discovery to create a fission weapon. Clark recapitulates, thereafter, the growing Allied belief that nuclear weaponry (in the words of Churchill's scientific advisor) gave a nation the ability ""to dictate terms to the rest of the world."" But his interpretation of the Anglo-American debates over the political uses of nuclear hegemony lacks the depth of works by mainstream writers (Feis, Smith) or revisionists (Kolko, Alperovitz); and on the Russian challenge, and the Allied response, his text is superseded by the relatively recent writing of Martin Sherwim (A World Destroyed, 1975) and the very recent contributions of Gregg Herken (The Winning Weapon, K. 1980, p. 1610). But given the lack of a popular, accessible account of the development of nuclear weaponry, the first two-thirds of the book, at least, will be of reference value.