Clausewitz's On War, first published in 1832, remains the most famous study of the nature and conditions of warfare. Contemporaries found him 'endearing' or 'totally unpalatable', while later generations called him 'the father of modern strategical study', whose tenets have 'eternal relevance', or dismissed him as outdated. Was it really he who made the discovery that warfare is a continuation of politics? Was he the 'Mahdi of mass and mutual...