Visiting Tbilisi long years ago, I asked confidently if I could see the bank in Yerevan Square that was robbed by Stalin and his friends in 1907, imagining that it might well be a tourist attraction. Blank faces all round. The famous Georgian was still a national hero as recently as the 1980s, but the notion that he had been part of a Butch Cassidy band did not appear in the official biographies. This, they said, was a Menshevik smear.

The British pay equally little attention to Stalin's brief stay in the East End of London two months earlier, at 77 Jubilee Street, off the Whitechapel Road. His lodging house, long gone, is now a municipal housing estate, with no blue plaque to be seen. Maybe the authorities think he is best forgotten, though that is not the view of writers and publishers. The shelf space devoted to biographies of Stalin grows bigger by the year - though it is still some way from rivalling the space devoted to Hitler. Yet Stalin ruled for longer and was an infinitely more interesting man.

The latest in the field is Robert Service, the distinguished historian of Russia who has already completed a mammoth and well-regarded life of Lenin. His Stalin is an elusive and complex figure who bestrode Soviet life for more than a quarter of a century, presiding over the emergence of Russia as a great industrial and political power that wielded influence on a global scale. Although an intellectual, a writer and editor, an absolutely tireless worker and a dedicated Bolshevik, Service's Stalin remains at heart a ruthless killer, a man who avoids counting the human cost of one of the most astonishing social experiments in history. Service tries to present a fresh and nuanced account, but he follows up every faintly positive judgement with a reminder of how unpleasant Stalin was - "a mass killer with psychological obsessions" - lest the reader forget.

This biography casts fresh light on many ignored aspects of Stalin's early career - his imprisonment in Siberia, his neglected role in the October revolution, his military command during the civil war and his conflicts with Lenin. His emergence as the pre-eminent figure among the warring Bolsheviks after Lenin's death comes to appear not just understandable, but virtually inevitable. Stalin was often dismissed by his colleagues as a mere "administrator"; they understood too late that this was the supreme talent necessary for running a bureaucratic state - much as colourless individuals become the bosses of large companies from the apparently lowly position of "accountant".

Service rightly awards Stalin high marks for his philosophical work on the nationalities question, published in 1913. Stalin had been handed the task by Lenin, who knew that the man he called "the wonderful Georgian", with his intimate knowledge of the many Caucasian groupings which have caused problems from that day to this, would have a sharper insight into the subject than any of the more overtly intellectual Bolsheviks. Theoretically, Stalin was hostile to nationalism, arguing (against the Mensheviks) that "national character" was not some "given fact", but something that changed "accor-ding to the conditions of life". Yet he was in favour of regional self-government, and believed that "the right of secession" should be extended to all nations - with the hope that none would take up the offer. In the early years of the Soviet Union, few showed any desire to do so.

Stalin's theoretical way of dealing with the Chechens and the like was considerably more progressive than that today of Vladimir Putin, though when called upon to put his ideas into practice during the Second World War he was comparably brutal. Half a million Chechens were sent off to camps in the east in 1944, on the dubious report that some had exhibited sympathy for the German cause.

Stalin will be remembered more for his murderous activities than for his progressive views on the national question, and here Service makes little attempt to prevent his anger from overcoming his scholarly reserve. The slaughter of the kulaks, the "Great Terror" of 1937-39 and the ruthless conduct of the war against Hitler are outlined in all their gory detail.

Unlike earlier biographers of Stalin, Service clearly believes he was little different from other Bolshevik leaders, and that the terror which characterised periods of his rule was implicit in the Bolshevik project from the start. This view, common since the collapse of communism, and always challenged by supporters of Trotsky, is one with which I have some sympathy. None the less, it creates a structural problem for a biographer, called upon to define the specific nature of Stalin's contribution to history. If all Bolsheviks are equally guilty, then Stalin's role becomes less interesting.

Service is often an awkward and jerky writer, and his efforts to rise above the pedestrian produce unfortunate sentences such as: "The Lenin cult glistened like a film of oil over the dark ocean of Soviet reality." His book will do little to diminish the paperback sales of Simon Sebag Montefiore's Stalin: the court of the red tsar, last year's offering on the subject. Montefiore's book is salacious and novelettish, but it is a lively read, enhanced by many interviews with surviving players of the Stalin era. Service's book, by contrast, is that of a professional historian with few journalistic skills, who depends almost entirely on the printed word and the archives. His lamentable efforts to follow Montefiore into Stalin's bedroom are couched in a strangely juvenile language. We are told how Stalin "got over his wife's death with unseemly haste and . . . chased skirt with enthusiasm". Elsewhere, a man whose wife had attracted Stalin's attention is said to have feared that the friendship "might lead to hanky-panky".

In the end, Service's Stalin is a disappointment, simply not in the same league as Ian Kershaw's Hitler. Too often, he steers judiciously between rival versions of Stalin's life without presenting a considered view of his own, and sometimes it seems that the much-signalled references to "hitherto unpublished material in the Moscow archives" do not add much to a story whose outlines are already familiar. Many historians will have to beaver away in those archives for many years before their true worth becomes clear.

Richard Gott's latest book, Cuba: a new history, is published by Yale University Press this month