Before the Fall-out: From Marie Curie to Hiroshima, by Diana Preston

Langevin was more perceptive than the average physicist of his generation. For most of his colleagues, the real world was an abstraction. Robert Oppenheimer, for instance, apparently did not know of the Great Depression until around 1935. It was perhaps dangerous for men so detached from life, and so young, to meddle with atoms. But the nuclear physicists considered themselves theoreticians, not engineers.

They were not building a bomb; merely musing on the structure of the atom. They thought they could ignore nation states since their first loyalty was to science. To most of them, their research seemed as harmless as that of a mathematician who searches for higher and higher prime numbers. Ernest Rutherford, the first man to "split" the atom, went to his grave in 1937 believing that those who spoke of exploiting nuclear energy were "talking moonshine".

The life story of the atom bomb is a morality tale, a chronicle of innocence lost. Those who started out in seemingly innocuous arcane research became servants of the state, building deadly weapons. Within the atom enormous power lurked, and all nations are covetous of power.

It is easy, knowing what we do now, to criticise the scientists who opened the Pandora's Box of nuclear research. They seem naïve and irresponsible. But naïveté is a weakness which arises from the assumption that the world is a better place than in fact it is. As Diana Preston argues in Before the Fall-out, the common feature of the atomic scientists was that they were all "only human".

Preston describes what she calls the "human chain reaction" which started with Marie Curie's discovery of radium in 1903 and ended with the destruction of Hiroshima, 42 years later. Her book is about people - rightly so, since the building of the atom bomb was, first and foremost, a triumph of human intelligence, creativity and will. The discussion moves effortlessly between labs in Cambridge, Göttingen, Copenhagen, Paris, Moscow and Berkeley, tracing the development of the world's most fearsome weapon. There's nothing particularly new to her story, but it is told with flair.

The author loves detail, no matter how small. We learn of Curie's scandalous affairs, and that Rutherford did not like kidneys for breakfast. Chadwick had a weak stomach which could not tolerate oysters and Otto Hahn, whose English was not very good, had a tendency towards malapropisms which offended the sensibilities of polite young ladies. These trivialities are obviously intended to give texture to the human story of the bomb but, before long, because of their ubiquity they're about as welcome as ants at a picnic.

The great fault of this book is that it is loaded with detail but lacking in depth. It's not unlike Hello! magazine; we're given loads of useless information about lots of people, but not much in the way of real insight which would allow us to understand them. For instance, Preston includes the famous quote from Oppenheimer, uttered after the first atomic explosion, that he was a little scared of what he had made. But the utterance is left hanging; Preston does not probe into his moral anguish.

Nor are we given much on the emotions behind the decision to deploy the bomb over Hiroshima. Preston is correct to see its use as inevitable. She quotes General Leslie Groves, military head of the Manhattan Project, who described Truman as like a boy speeding down a snowy hill on a toboggan, with no real means of stopping or steering. That is an effective metaphor, but to understand why requires an appreciation of the moral and political currents of the early 20th century. Instead of the detail about the dietary habits of atomic physicists, I would have liked a discussion of how it came to pass that killing 140,000 civilians with a single bomb was a legitimate means of waging war.

The atom bomb is a story of people, but also much more than that. The destruction of Hiroshima occurred not just because a chain of human beings discovered how to unlock the power that lay within the atom. It also occurred because of much more complex moral developments bubbling beneath the surface, like molten lava ready to erupt.

Before 1945, science was thought benign; any discovery was automatically seen as progress. At the same time, the legal definition of war was widened in order to accommodate what the scientists provided. Killing kids became acceptable because it became possible. Military capability was the mother of moral justification.

This book reminds me of typical fare at a summer fête - lots of tasty titbits, but nothing substantial. Preston loves to tell stories, and she is quite good at it, but seems strangely averse to analysis. As a result, the reader gains a superficial knowledge of what happened, but no real understanding of why.

In the place of analysis, we're given a rather strange epilogue which consists entirely of tempting counterfactuals - what ifs. Some of these are intriguing, others frankly bizarre. Preston, for instance, suggests that if the Danish physicist Bohr had not been a mumbler, the warnings he gave Roosevelt and Churchill in early 1945 might have been more clearly understood and Hiroshima might not have been bombed. The author claims that questions of "what if" litter history. Answers to them can inherently never be certain and therefore "they attract historians like bees to honey".

I'm not sure which historians she hangs out with, but most of those I know are more responsible. Most professional historians are satisfied to analyse what happened instead of speculating wildly about what might have been.

The 60th anniversary of Hiroshima is attracting a lot of interest in the atom bomb. Those new to the subject might find Preston's book interesting. But an event of such immense magnitude deserves more depth and insight than she is able to provide.

Gerard DeGroot's 'The Bomb: a history of hell on earth', which won the RUSI/Westminster Medal for Military Literature, is published by Pimlico