(FORTUNE Magazine) – The First World War By John Keegan Knopf, 512 pages

Serbian nationalists commit an act of violence, and a decision to punish them is made by a group of allied nations. A chain reaction among neighboring countries leaves millions slain and whole swaths of Europe laid waste. This isn't a prediction about the ongoing conflict in the Balkans but, of course, the story of World War I in a nutshell. As he has done in previous books, eminent British military historian John Keegan, author of A History of Warfare and The Face of Battle, peers closely at warfare's nuts and bolts to render an epic tale. The First World War isn't history for Big Picture enthusiasts who crave cultural and social context. Instead, Keegan examines warfare at a transitional historical moment when cavalry, tanks, sabers, and machine guns all shared the battlefield.

This unevenness of technological advancement, Keegan emphasizes, contributed to the breathtaking casualties--more than nine million soldiers died--chiefly because the speed of communication lagged far behind the power of the weaponry. Runners or flag signalers alerted generals to battlefield changes much too late for them to act effectively, yet those officers had at their disposal unprecedentedly potent weaponry. At the Battle of the Somme, a British attempt to lay a creeping cannon barrage just ahead of advancing British troops failed because without tactical radio, the artillery fired based on a calculation of the speed at which the men were expected to advance. Cautious artillery gunners lifted their barrages too soon, exposing long lines of close-order troops to unimpeded enemy fire. More than 20,000 British infantrymen were killed in a single day.

Keegan also argues convincingly that strategic geography was crucial to creating the deadly stalemate reached early in the war. Although the Germans attacked first, they also assumed defensive positions first--as soon as they realized quick victory in France was impossible and a second front had opened in Russia. They were able to choose the advantageous high ground and fortify it well. While the British cavalry took pride in avoiding entrenchment and the French disregarded "the most demanding notions of cover," Keegan writes, "the German soldier had been obliged to use the spade on manoeuvre since at least 1904." As a result the Germans were hardly touched by the million shells lobbed by the British at the Somme; they sat snugly in deep trenches equipped with beds, electric lights, carpets, and pictures. Amid all the new technologies of the war--tanks, poison gas, planes, machine guns--one of the most influential factors may have been the lowly shovel.

The horrific casualty rates of World War I have long sparked vigorous criticism of generals--"donkeys leading lions"--who seemed indifferent to the appalling loss of life. Most notorious was British commander Douglas Haig, who became known after the war as "Butcher Haig." Acknowledging Haig's "profligacy with men," Keegan claims the high command was generally brave and responsible. He compares statistics from World War I, in which 56 British generals were killed, to those of World War II, when only 21 were killed. He also defends the practice of establishing headquarters well behind the lines with the rationale that vast battlefronts, often many miles long, required central repositories for information. But when the reader is confronted with the image of Haig--lunching, working at his desk, and preparing for bed as thousands died--disgust is almost unavoidable.

This perception of official callousness, the grinding brutality of the conflict, and its general pointlessness, which emerged as the reasons for fighting were forgotten, dispirited the most patriotic soldiers. Keegan writes of the 25,000 German soldiers buried in a common grave in France at Langemarck, where the cemetery gate bears the insignia of every German university. This was no war fought only by the poor and unlucky, but rather one in which the best and brightest rushed for glory and honor. As Paul Fussell wrote in The Great War and Modern Memory, his blistering look at the war's social consequences, the words "glory" and "honor" would never be the same after bloodbaths at the Somme, Verdun, and Passchendaele. A fit companion to Fussell's great cultural meditation (and to this season's other World War I tome, Niall Ferguson's The Pity of War), Keegan's ground-level focus makes us keenly aware of how battles are fought, won, and lost, and reminds us that like politics, all wars are local.

--Albert Mobilio