Clausewitz, Carl Philip Gottlieb von (1780-1831), Prussian general and theorist of war. His posthumously published work On War (1832) is the most important general treatment of its subject yet produced. Clausewitz entered the Prussian army as a 12-year-old in the spring of 1792, and was soon drawn into the French Revolutionary wars that began a few weeks before. The following year he fought in the Rhineland and the Vosges, indecisive campaigns of position and manoeuvre typical of what would soon be called ‘the Old Regime’, but sufficient for the moment to bring peace to northern Germany. In 1801 he was admitted to the Institute for Young Officers in Berlin. There he came into contact with the Institute superintendent, Gerhard von Scharnhorst, the seminal intellectual influence of Clausewitz's life. Scharnhorst was among the first to recognize that the French Revolution would transform the conduct of war, and that the social and political institutions it was creating would in turn create new military possibilities which the conservative monarchies of central Europe would be hard-pressed to match. Clausewitz's earliest surviving manuscripts date from his years at the Institute. They reveal a mind already engaged by questions of the broadest military and political significance.
Scharnhorst's insights were vindicated in October 1806, when the forces of Napoleonic France crushed those of Prussia at the twin battles of Jena/Auerstadt. Clausewitz was present as adjunct to the king's nephew. In the retreat that followed he assumed command of part of the rearguard—the only time he commanded troops in combat—and eventually spent seven months interned in France. Upon his return he became involved in the movement to reform the Prussian state and army, in which Scharnhorst, again, was a key figure. In 1812, following Prussia's acceptance of a French alliance, which Clausewitz found politically and emotionally intolerable, he resigned his commission and, along with some 30 other Prussian officers, went to serve in Russia. There he witnessed the epic campaign that would break Napoleon's hold on Europe, a process to which Clausewitz made a modest personal contribution as negotiator, on the Russian side, of the Convention of Tauroggen, by which the Prussian contingent of the Grande Armée withdrew from the war.
As the war moved back into central Europe, Clausewitz worked to raise provincial militia and other irregular forces against the French, activity that was judged treasonous by some since, like the Convention of Tauroggen, it was done without the king's consent. He regained his Prussian commission in April 1814, and was COS to a corps during the Waterloo campaign. In 1818 he became superintendent of the Allgemeine Kriegsschule (War College) in Berlin, a purely administrative post that did not require him to teach, but did afford time for historical and theoretical work. In 1831 he set his studies aside when the outbreak of civil war in Poland caused Prussia to mobilize part of its army. Clausewitz was chosen as COS of the forces deployed to observe the conflict. He died in Breslau of cholera a few months later.
On War was published by Clausewitz's wife the following year. It has always been judged a demanding text, in part because it was never subjected to the comprehensive revision Clausewitz knew it required. The book is thus marred by inconsistencies and omissions that further work would presumably have reduced. On the other hand, anyone familiar with the first chapter of book 1, the only part that Clausewitz declared finished to his satisfaction, may wonder whether, if the entire book had been brought to a comparable state of theoretical density and analytic precision, the results would be any easier to interpret. In the end, whatever difficulty On War poses for the reader does not arise from its accidental shortcomings, but from its author's intellectual ambition.
On War is only secondarily a work of strategic theory, if by that one means a work intended to improve our ability to wage war successfully. Clausewitz had his own ideas about the best way to conduct military operations, and much of On War is devoted to strategic and tactical analyses that were certainly intended to appeal to the practical instincts of other professional soldiers. Yet his study of the history of war had also made him aware that his insights would some day lose whatever practical value they might possess for their own time. His ultimate goal was therefore to reach beyond such instrumental concerns, in order to grasp war as a total phenomenon, and understand its relationship to the social and political world of which it is a part. The result is a work whose most essential propositions are so encompassing that they might be easily mistaken for truisms: that the essence of war is violence, which knows no natural limit; that war ‘does not consist in a single blow’, but involves protracted interaction between opposing wills; that every attack loses impetus as it proceeds, until it reaches a culminating point where it no longer exceeds the strength of the defence that opposes it; that war is dominated by chaos and chance, which Clausewitz characterizes metaphorically as friction; that military genius can be cultivated, but not taught; that the only means in war is combat; that war is merely a continuation of policy; and so on. Theory at this level cannot serve as a guide to action, and is not intended to. On War is not about how to fight. It is about how to think about war.
For Clausewitz, one requirement for clear thinking was an unflinching respect for war's physical, psychological, and historical reality. He disdained bold strategizing that took no account of how difficult the simplest action becomes in the ‘resistant medium’ of war. He recognized the impact of fear, danger, confusion, and fatigue on men in battle, and wrote about them with unusual candour. He also rejected the idea that contemporary military methods represented a normative standard against which past practices could be judged. If wars in the past rarely achieved the scale and violence of Napoleon's greatest campaigns, it did not mean that previous generations had somehow failed to grasp a science whose true principles had now been revealed. For Clausewitz, the goal of theory was not to transpose reality into a system of abstractions, but to illuminate it with as little intellectual distortion as possible. No theory could be adequate that did not account for the full range of military experience captured in the historical record. That record suggested that war at all times possessed what Clausewitz called a ‘dual nature’. Few wars were ever intended to overthrow the enemy completely. Most sought limited goals, and were accordingly fought by limited means.
Clausewitz's recognition of the theoretical significance of limited war was both a consequence and a source of his insight into war's political and instrumental character. Clausewitz was scarcely the first to see that wars arise from political quarrels, or that they answer to purposes beyond themselves—that they are ‘about’ something. But he was the first to recognize the analytic power that these perceptions possessed when rigorously applied to all aspects of war.
For Clausewitz, the ‘subordination’ and ‘permeation’ of war by politics meant that there could be no ‘purely military solution’ to any military problem. It also exemplified a kind of complex tension that always attracted him. War, he famously proposed, was a ‘remarkable trinity’, whose essential elements—primordial violence and passion, the ‘free play’ of chance and creativity on the battlefield, and intelligent political purpose—could never be fixed in any arbitrary relationship. War's subordination to politics was logically necessary, and the norm in practice. Yet it was never perfect or absolute. War always threatened to escape its political restraints, and often did succeed in modifying the course of policy to some extent. The violence of war and the rationality of politics were thus theoretical opposites whose real existence was nevertheless marked not by mutual repulsion or exclusion, but by intense and continuous interaction.
Similarly dynamic conceptual structures—which in Clausewitz's day would have been described as ‘dialectical’—pervade On War at every level. Violence and reason, genius and friction, attack and defence, risk and decisiveness, ends and means, fear and courage, victory and defeat—such dualities weave their way throughout the text like musical figures, echoing and recurring in unexpected registers that may sometimes startle or disconcert us, but which finally provide the work with an intellectual integrity that transcends its superficial incongruities. In a note written towards what proved to be the end of his life, Clausewitz openly feared that his work would be liable to ‘endless misinterpretation’ and ‘much half-baked criticism’, an apprehension that has been borne out more than once. Yet his ultimate ambition—‘to write a book that would not be forgotten after two or three years’—would also be amply fulfilled. Few comparably demanding works in any field have so thoroughly withstood the test of time.
Bibliography
- Carl von Clausewitz: Historical and Political Writings, ed. Peter Paret and Daniel Moran (Princeton, 1992).
- Aron, Raymond, Clausewitz: Philosopher of War (New York, 1983), trans. from German orig. (1980).
- Paret, Peter, Clausewitz and the State (Oxford, 1976)
— Daniel Moran









War is regarded as nothing but the continuation of state policy with other means.
