Secrets kept too well hidden

Michael Caine likes to explain the unevenness in the quality of his output as an actor with the line that if you have a very high standard of living, you sometimes have to make a very low standard of film. The prolific Andrew Roberts brings to mind the same problem. His Salisbury was excellent, and his Napoleon and Wellington entertaining, but Hitler and Churchill , a tie-in book for a BBC television series, while by no means as bad as Caine's performance in Dirty Rotten Scoundrels , is not Roberts' finest hour.

It is not banal - Roberts is rarely that - although it sometimes slips into a kind of camouflaged superficiality that sneaks under the radar of the fast reader. He writes: "The creation of an all-encompassing national legend is epicentral to the formation of a modern political movement." This and many other sub-political-science utterances are offered without evidence, an analytical framework or even supporting examples. The less you think about them, the more impressive they sound.

Indeed, Roberts is an extremely talented narrative historian of the old school. Like Robert Blake he can tell a good story, and his command of sources, including here as-yet-untranslated German military sources, is awesome. But his books lack ideas; moreover, they wear their lack as a badge of honour. This does not matter much when they are narratives of individual lives (Salisbury, Halifax), or even when they compare like with like (Napoleon and Wellington). But when the comparison is contextually complex, the narrative approach breaks down and the analytical simplifications prove inadequate.

The book opens with some quality journalism on the nature of leadership that cites some of the immense literature in this field but omits even more, such as Weber on charisma. It ends with a brilliant dissection of the Churchill revisionists. David Irving, John Charmley et al are lined up and shot down with devastating simplicity and precision.

But the main body of the book reads as though the author has sat down with the index of Martin Gilbert's study of Churchill and of Ian Kershaw's books on Hitler and cross-referenced them to create a narrative. It reads like research for a television programme written up as a book. The joins are far from seamless.

Despite the subtitle, very few secrets of leaderships are actually revealed. An error that states that followers of great leaders, in order to accept the leader's omnipotence, must suspend "belief", rather than "disbelief", is surely indicative of both the speed of production and the superficiality of the analysis. There is little else in common to point to.

Churchill was a democratic politician who worked as part of a team. He relied on the deaths of other nationals - mostly Russians and Americans - to achieve his objectives. Hitler was a dictator who was directly responsible for the murder of 6 million Jews and millions of other racial and political groupings and the deaths of many millions of Germans. The political, moral, personal and historical contexts of the two leaders were so different as to render a convincing comparison impossible without propounding a wholly new theory of politics.

One imagines that when the author reaches the genuine state of old fogeydom at which he currently merely plays, this book will be submerged beneath a large pile of longer, better and more interesting narrative histories. I hope he does not attempt a further novel. Like Churchill, whose fictional excursion has been justifiably ignored by most writers apart from Roberts, fiction is not his forte. He should return to doing what he does best: putting forward the case for a Conservative interpretation of history.

Brian Brivati is professor of contemporary history, Kingston University.