Perhaps the most important book on military strategy ever written, Carl von Clausewitz’s On War has influenced generations of generals and politicians, has been blamed for the unprecedented death tolls in the First and Second World Wars, and is required reading at military academies to this day. But On War, which was never finished and was published posthumously, is obscure and fundamentally contradictory. What Clausewitz declares in book 1, he discounts in book 8. The language is confusing and the relevance not always clear. It is an extremely difficult book for the general reader to approach, to reconcile with itself, and to place in context. Hew Strachan, one of the world’s foremost military historians answers these problems. He explains how and why On War was written, elucidates what Clausewitz meant, and offers insight into the book’s continuing significance. This is a must read for fans of military history.