'War is merely the continuation of policy by other means'
Required reading at West Point and Sandhurst, a major influence on Lenin and Mao Zedong and read cover to cover no fewer than three times by Eisenhower, Clausewitz’s magnum opus is one of the most important studies of warfare, military strategy and philosophy ever written. In 1943, Allied bombers dropped leaflets over Germany asserting that Hitler had not read and understood On War properly. Such was Clausewitz’s stature in Germany that Hitler felt forced to reply.
Carl von Clausewitz joined the Prussian army in 1792 at the age of 12. For much of his long military career the Napoleonic Wars raged, and the young officer witnessed and sought to understand Napoleon’s genius on the battlefield, despite opposing him wholeheartedly. He took part in the Waterloo campaign that saw Napoleon’s final defeat. Promoted to major general, Clausewitz ran the prestigious military academy in Berlin where he wrote the bulk of On War, but was recalled to active duty. His great work was published posthumously and quickly achieved a remarkable influence.
Some historians labelled Clausewitz an architect of Prussian militarism and felt that his theories led to the ‘total war’ propounded in the First and Second World Wars. In fact, his philosophy was much more complete and nuanced. He had a pragmatic, clear-sighted view of military action, despite a personal repugnance for the horror of war. He asserts that ‘gradually blunting our swords in the name of humanity’ is foolish: ‘Sooner or later someone will come along with a sharp sword and hack off our arms.’ As a strategist, he believed in independent thinking, not doctrine, and repeatedly emphasises that every war is the unique product of its social, economic and political conditions.
As happened with the 4th-century treatise The Art of War, dicta from On War have been extracted and applied to activities outside professional soldiering, from game theory to business. In her foreword, historian Joanna Bourke, author of several books on war and violence, reveals that the issues Clausewitz explores remain of immense concern today: militarism, the ethics of slaughter, the distinction between abstract war and war in its bloody reality, the role of leaders, and political control over the military.