Sometimes sheer length in a biography just means the author couldn't bear to leave out any of those painstakingly researched details. But in the case of J. Robert Oppenheimer, father of the atomic bomb, it's hard to imagine telling his story in fewer pages than this.

Oppenheimer is known both for his achievement and for his downfall. When a decision was made to seek a new weapon that could help end the threat of Nazism, the U.S. government was perceptive enough to recognize that a young physicist named Oppenheimer was the one who could build and motivate a team to get the job done. Years later, when the political tide had turned, that same U.S. government subjected him to a devastating campaign of character assassination.

Researched by Martin J. Sherwin beginning in 1979, and completed with the help of Kai Bird, American Prometheus tells a complicated story with grace and clarity. The book is especially strong in tracing Oppenheimer's mental and psychological development, beginning with his childhood as the child of a cultured Jewish family in New York City, where his social conscience was formed by his schooling in the Ethical Culture movement.

The authors admit that interviews and research cannot solve every question. Oppenheimer's transformation from an awkward young intellectual to the charismatic leader of a world-class scientific team may always be mysterious. It was in Oppenheimer's nature to generate opposing opinions. He could be witheringly contemptuous or seductively charming. To their credit, in areas where opinions differ — such as the nature of Oppenheimer's family life — the authors quote sources with opposing opinions.

Despite its length and thoroughness, American Prometheus has some gaps. For instance, the relationship between Oppenheimer, the father of the A-bomb, and Edward Teller, the father of the H-bomb, is frustratingly unexplored. Teller's devotion to creating a “Super” bomb was so extreme that he lost interest in the ordinary atomic bomb even before it was finished. Where did this strange drive come from? The authors don't say.

The technical aspect of Oppenheimer's achievement also gets short shrift. How exactly did he succeed in focusing his team on the technical challenges that would lead to a workable bomb? On that subject, The Making of the Atomic Bomb by Richard Rhodes is still the indispensable source.

Altogether, though, American Prometheus tells a compelling story with considerable psychological insight. It is especially good at teasing out the extent and implications of Oppenheimer's involvement with leftist causes and the Communist Party, and his twisted relationship with the elusive Haakon Chevalier and the vindictive Lewis Strauss. In the end, it seems, it was not his Communist affiliations that were his downfall, but his efforts to halt the arms race with the Soviet Union before it could begin. Modern history might have looked very different if he had succeeded.