Born June 1, 1780, in Burg, near Magdeburg; died Nov. 16, 1831, in Breslau (now Wroclaw), Poland. German military theorist and historian; Prussian general. Son of an excise official.

Clausewitz entered the Prussian Army in 1792. He graduated from the German War School in Berlin in 1803, was an adjutant of Prince August of Prussia until 1808, and served in the war with France of 1806–07. In 1808–09 he was chief of the office of General G. von Scharnhorst’s Military Reorganization Commission and was active in preparing for the reorganization of the army. Clausewitz taught at the German War School from 1810 to 1812, and wrote his Survey of Military Training (Major Principles of War). He was the author of Three Confessions (February 1812), a patriotic document of the group of military reformers (Scharnhorst, Gneisenau, and Boyen), in which was set forth the idea of a popular war in alliance with Russia against Napoleon’s domination. In the spring of 1812 he left Prussia and entered the service of the Russian Army. During the Patriotic War of 1812, Clausewitz served as quartermaster in the cavalry corps of P. P. Palen (subsequently commanded by F. P. Uvarov) and after October 1812 on the staff of P. Kh. Witgenshtein’s corps (later army). In 1813 he was liaison officer for G. Blücher’s Prussian army and after August 1813, chief of staff of L. Wallmoden’s corps. In April 1814, Clausewitz reentered the Prussian service and was chief of staff of a corps. He was director of the German War School from 1818 to 1830. In the latter year he was appointed inspector of artillery and in 1831, chief of staff of a Prussian army on the Polish border. He died of cholera.

Clausewitz’ world view was formed under the influence of the ideas of the French Revolution and the national liberation movement of the peoples of Europe in the early 19th century. He held moderate bourgeois views, combining progressive ideas and a sharp critique of the feudal military system with reactionary and antidemocratic ideas and Prussian nationalism. His views were based on the idealist philosophy of G. Hegel, I. Kant, and J. G. Fichte. Clausewitz was the first thinker to apply the dialectical method to military theory in his consideration of the interrelation and development of the various phenomena of the art of warfare. He made a thorough study of more than 130 campaigns and wars between 1566 and 1815 and wrote a number of works on military history. His main work is the three-volume study On War (Russian translation, 1932–36), which presents his views on the nature of war and on the forms and methods of warfare.

Clausewitz’ contribution to military theory made up an entire stage in the development of 19th-century military thought. Many of his propositions are still valid. The classics of Marxism-Leninism had a high regard for his contributions. F. Engels believed that in Clausewitz, German literature had presented to the world a star of the first magnitude. V. I. Lenin called him “one of the greatest authorities on military matters” (Poln. sobr. soch., 5th ed., vol. 36, p. 292), “whose main ideas have now definitely become the possession of every thinking person” (ibid., vol. 32, p. 79). A central place in Clausewitz’ scholarly achievements is occupied by his proposition about the relation of war and politics: “War is the continuation of politics by other means,” and politics contains in a hidden form the main outlines of a future war. “Marxists have always rightly regarded this thesis as the theoretical basis of views on the significance of any war” (ibid., vol. 26, p. 316).

However, being an idealist, Clausewitz viewed the politics of a state as representing the interests of the whole nation and failed to understand the moving force of the development of politics itself, namely, the class struggle. Clausewitz correctly asserted that “every epoch has its own wars” and that changes in the art of warfare are caused by “new social conditions and relations.” He could not understand, however, the ultimate causes of the development of the art of warfare, and his explanation of them was rather contradictory.

Clausewitz made a great contribution to the theory of warfare and its component parts—strategy and tactics. He established a number of strategic principles necessary to attain victory (complete exertion of all forces, maximum concentration of forces on the axis of the main strike, speed and suddenness of action, and vigorous exploitation of success). By skillfully applying the dialectical method, Clausewitz correctly solved such problems as the relation between the offensive and the defense and the importance of army morale. He attached great importance to matériel, geographical, and morale factors and the role of the military leader.