In 1918, the American colonists were loyal subjects of the British crown, the British army crushed the Russians at Vienna with a roar of musketry and cavalry charges, the British navy unveiled its secret weapon (fireships), and the British king--after personally leading his men in battle--claimed the title of King of France. Or so went a less-than-accurate prediction from 1763 entitled The Reign of George VI, 1900-1925. It was the first of a long line of fiction forecasting the shape of wars to come. In Voices Prophesying War, I.F. Clarke provides a fascinating history of this unusual genre--a strand of fiction that has revealed more about contemporary concerns than the direction of the future. The real surge of fiction about future wars, he writes, took place after the Franco-Prussian War of 1870-71. Clarke skillfully evokes the context of fear and political tension that gripped Britain after the German victory as he describes a wave of stories that predicted a foreign conquest of England. Starting with The Battle of Dorking (an account of a German invasion that was later translated and issued by the Nazis in 1940), forecasts of a future catastrophic war led to an invasion scare and a demand for military reforms. The French, too, fought fictional wars with Germany over Alsace-Lorraine (and occasionally with Britain), taking revenge in print for their humiliating defeat in 1871. The tense years just before World War I spawned another surge of fiction predicting the next great war, (leading G.K. Chesterton to publish a hilarious parody, The Swoop! or, How Clarence Saved England, depicting an attack by eight separate enemies on an England so indifferent that the newspapers report the invasion with the cricket scores). But Clarke shows how the predictions were taken seriously by the public and the military authorities. In 1906, Field Marshal Lord Roberts collaborated on an invasion scare story to promote his campaign for a larger army (and the newspaper that published it had him reroute the invaders, to take them through its strongest markets). Ironically, the most accurate predictions (including a story about unrestricted submarine warfare by Arthur Conan Doyle) were derided as implausible. Clarke follows the genre though to the present day, looking at how the Cold War shaped speculative war fiction and even science fiction accounts of conflict in the distant future. The end of the Cold War, he notes, has left writers floundering in their search for a believable enemy. No author, he writes, was as remarkably prescient as H.G. Wells, who foresaw atomic bombs as early as 1913. But, as Clarke shows, writers have yet to give up trying to predict the wars to come--offering a window into the fears of the present.