Both military history and the railways regularly generate large numbers of publications, with even the small details of minor events often covered in copious detail by numerous different authors. Strange then that the overlap of the two, the role of railways in military history, has generated little attention and no over-arching standard history. Christian Wolmar's Engines of War looks to put that right, and makes an extremely good attempt.
Wolmar's expertise lies in the railways rather than military history and he is refreshingly frank about the limitations of his knowledge of the latter. He has acquired sufficient such knowledge to make the book work well in most parts, though he places too much reliance on AJP Taylor and Winston Churchill at times. Both are very readable, extremely persuasive but also highly controversial historians and to have either as your basic source of information on events is a risky approach. That is the approach that Wolmar takes and as a result, his narrative sometimes suffers. His partial debunking of Taylor's views on the origins of the First World War, for example, make for a slightly quaint distraction given how much the debate over its origins has moved on anyway since his time.
The other blemish in the book is the paucity and limited detail of the maps, a real shame in a book that relies so much on accounts in which the relative location of places and the geography of the intervening landscape is crucial.
Neither blemish however seriously damages the book's attempts to entertain or educate, both of which it does admirably. His main thesis is that it was only the development of the railways which made the increasingly large, and so logistically cumbersome, armies of the nineteenth and twentieth centuries possible. In the end, however, the railways were also their undoing because defenders could always call up reinforcements far more quickly than attackers who, as they advanced, went beyond the reach of their own rail networks. The result was that stalemate was the norm until the development of reliable motorisation increasingly freed armies from railways.
One side-story which comes up frequently is just how hard railways were to destroy. A bit of damage here and there was easy, but could also be quickly repaired. It was only well into the twentieth century that explosives made large-scale destruction of railways, at least in rugged terrain that required bridges, viaducts and the like, quick and reliable. Until then, the possibilities of speedy repair had made railways a rather robust form of transport.
Another aspect briefly touched on is how railways offer another example of technological development which could both undermine dictatorships yet also strengthen them (cf the debate over The Net Delusion: How Not to Liberate The World). In the case of railways, they both allowed dissidents and dissident ideas to move around but also permitted troops to be despatched quickly to quell unrest.
As these two examples illustrate, there is much to enjoy in this book even if you are neither a serious fan of military history nor of railways.