Carl von Clausewitz

• 1. Introduction

  ›

  Carl von Clausewitz was born on the 1st of July 1780 in Burg bei Magdeburg, in the Prussian Duchy of Magdeburg. He died on the 16th of November 1831 of cholera, the same disease that had just killed the commander of the army he was serving. He was fifty-one years old, and his masterwork was unfinished. Yet the book his widow published the following year would go on to be mandatory reading in military academies worldwide, its concepts migrating into business strategy, sport, and nuclear deterrence. How does a manuscript left incomplete at its author's death become one of the most consequential texts in the philosophy of war? And how did a man who entered military service at twelve as a lance corporal eventually reshape how states think about power itself?

• 2. A Soldier's Formation

  ›

  Clausewitz's grandfather was the son of a Lutheran pastor who became a professor of theology. His father had served as a lieutenant under Frederick the Great before settling into a post in the Prussian internal-revenue service. Neither background was obviously military, yet at twelve years old Clausewitz joined the Prussian army as a lance corporal. By 1801, aged twenty-one, he had entered the Kriegsakademie in Berlin, where he came under the influence of General Gerhard von Scharnhorst, the future first chief-of-staff of the reformed Prussian Army. Scharnhorst appointed in 1809. Clausewitz became one of Scharnhorst's primary allies, working alongside Hermann von Boyen and Karl von Grolman to reform the Prussian army between 1807 and 1814.

  The catastrophe of 1806 proved formative in ways no academy could replicate. At the Battle of Jena-Auerstedt on the 14th of October 1806, Napoleon invaded Prussia and shattered the Prussian-Saxon army commanded by Karl Wilhelm Ferdinand, Duke of Brunswick. Clausewitz, serving as aide-de-camp to Prince August, was among the 25,000 prisoners taken that day as the Prussian army disintegrated. He was twenty-six. He was held prisoner with his prince in France from 1807 to 1808, and the experience of watching a great army collapse under French pressure never left his thinking.

  On the 10th of December 1810, Clausewitz married the socially prominent Countess Marie von Brühl, a member of an old German noble family originating in Thuringia, whom he had first met in 1803. The couple moved in the highest circles of Berlin's political, literary, and intellectual life. Marie was well-educated and politically well-connected; she played an active role in her husband's career and intellectual development, and would ultimately edit, publish, and introduce his collected works.

• 3. Against Napoleon, For Russia

  ›

  Opposed to Prussia's enforced alliance with Napoleon, Clausewitz made a decision that would shape both his career and his thinking about loyalty, politics, and war. He left the Prussian army and served in the Imperial Russian Army from 1812 to 1813, taking part in the Battle of Borodino in 1812. In the service of Russia, he helped negotiate the Convention of Tauroggen in 1812, an agreement that prepared the way for the coalition of Prussia, Russia, and the United Kingdom that ultimately defeated Napoleon.

  In 1813 Clausewitz joined the Russian-German Legion, as many Prussian officers serving in Russia did. By 1815 that legion had been integrated back into the Prussian Army, and Clausewitz re-entered Prussian service as a colonel. He was appointed chief-of-staff of Johann von Thielmann's III Corps in time for the Waterloo campaign.

  At the Battle of Ligny on the 16th of June 1815, south of Waterloo, Napoleon personally led an army that defeated the Prussians, though they withdrew in good order rather than collapsing. Napoleon's failure to destroy the Prussian forces at Ligny carried fatal consequences for him two days later at Waterloo on the 18th of June, when the Prussians arrived on his right flank to support the Anglo-Dutch forces pressing his front. Napoleon's own troops had been deceived into believing the approaching field-grey uniforms belonged to Marshal Grouchy's grenadiers. Meanwhile, Clausewitz's unit fought heavily outnumbered at Wavre on the 18th and the 19th of June, preventing large French reinforcements from reaching Napoleon at Waterloo.

• 4. The Unfinished Masterwork

  ›

  After the wars ended, Clausewitz served as director of the Kriegsakademie until 1830. He had begun working on what would become Vom Kriege, known in English as On War, in 1816. He never completed it. When he died in 1831, his widow Marie edited, published, and wrote the introduction to the text in 1832, and had published most of his collected works by 1835. She died in January 1836.

  On War contains material written at different stages in Clausewitz's intellectual evolution, which produces significant contradictions between sections. He had been working to revise the text, particularly between 1827 and his departure on his last field assignments, to include more material on "people's war" and forms of conflict beyond high-intensity state warfare. Relatively little of this revision made it into the published book. Clausewitz had relied on his own combat experience, contemporary accounts of Napoleon, and deep historical research; his historiographical instincts showed up even in his first extended study, written when he was twenty-five, on the Thirty Years' War.

  Soldiers before this time had written treatises on various military subjects. None had undertaken a great philosophical examination of war on the scale of those written by Clausewitz and Leo Tolstoy, both of whom were inspired by the events of the Napoleonic Era. More than sixteen major English-language books focused specifically on Clausewitz's work were published between 2005 and 2014. His nineteenth-century rival Antoine-Henri Jomini, by contrast, has faded from influence. The historian Lynn Montross explained this outcome by saying that Jomini produced a system of war while Clausewitz produced a philosophy: the one has been outdated by new weapons, while the other still influences the strategy behind those weapons.

• 5. The Trinity and Its Misreadings

  ›

  Clausewitz used a dialectical method throughout On War, and that method has generated persistent misreadings. His most famous phrase, "War is the continuation of policy with other means," is frequently quoted as a final definition of war. Christopher Bassford, then-professor of strategy at the National War College of the United States, has explained that the phrase was not intended as a statement of fact. It is the antithesis in a dialectical argument whose thesis is that "war is nothing but a duel on a larger scale." The synthesis resolving both bold statements is Clausewitz's "fascinating trinity" (wunderliche Dreifaltigkeit): a dynamic, inherently unstable interaction of violent emotion, chance, and rational calculation.

  The trinity is most often misrepresented as "people, army, and government," a reduction based on a later paragraph in the same section. This misrepresentation was popularised by U.S. Army Colonel Harry Summers during the Vietnam era, facilitated by weaknesses in the 1976 Howard-Paret translation. Bassford noted that the words "people," "army," and "government" appear nowhere at all in the actual list of the trinity's components.

  A separate misreading concerns total war. Clausewitz never used the phrase. He discussed "absolute war," which he treated as a logical fantasy, a purely theoretical extreme that the forces of competition would drive combatants toward in a Platonic ideal of war. In real war, he argued, such rigid logic is unrealistic and dangerous. The military objectives in real war generally fall into two broad types: limited aims or the effective disarming of the enemy. Martin van Creveld's 1991 book The Transformation of War declared the Clausewitzian Trinity an obsolete state-based construct. Daniel Moran and Christopher Bassford both replied that Creveld had attacked a position Clausewitz does not occupy.

• 6. Fog, Friction, and Genius

  ›

  Clausewitz was acutely skeptical of military intelligence at the tactical and operational levels. His own words from On War are direct: "Many intelligence reports in war are contradictory; even more are false, and most are uncertain. In short, most intelligence is false." His experiences in the Prussian Army contributed to this skepticism. The Prussian forces were often in an intelligence fog partly because of the superior abilities of Napoleon's system and partly because of the nature of war itself.

  Out of this challenge Clausewitz developed his concept of military genius, der kriegerische Genius. Genius in war is not simply a matter of intellect. It is a combination of intellect, experience, personality, and temperament that produces a highly developed mental aptitude for waging war. The concept applies most visibly in the execution of operations, precisely because friction, the disparity between the ideal performance of units and their actual performance in real-world scenarios, distorts all prior arrangements.

  These concepts have traveled far beyond military theory. The phrase "fog of war" derives from Clausewitz's stress on how confused warfare can seem from within. The term "center of gravity," used in a military context, derives from Clausewitz's usage, which he in turn took from Newtonian mechanics. In U.S. military doctrine, center of gravity refers to the basis of an opponent's power at the operational, strategic, or political level. The idea that friction distorts all prior arrangements has become common currency in fields including business strategy and sport.

• 7. A Global Afterlife

  ›

  Clausewitz directly influenced Karl Marx, Friedrich Engels, Vladimir Lenin, Leon Trotsky, Vo Nguyen Giap, Ferdinand Foch, and Mao Zedong. Lenin called him "one of the great military writers" and emphasized the inevitability of wars among capitalist states. The American mathematician Anatol Rapoport wrote in 1968 that Clausewitz as interpreted by Lenin formed the basis of all Soviet military thinking since 1917. The Russian historian A.N. Mertsalov observed the irony that Soviet doctrine attributed to Lenin a dictum taken from what Soviet orthodoxy considered an anti-humanist and anti-revolutionary.

  Mao Zedong read On War in 1938 and organised a seminar on Clausewitz for the Party leadership in Yan'an. The Clausewitzian content in Mao's writings reflects his own study, not merely a recycling of Lenin.

  In the United States, Clausewitz had little influence on military thought before 1945 outside of British writers, with some exceptions including Generals Eisenhower and Patton, both avid readers of English translations. Eisenhower's reading of On War as a young officer in the 1920s directly shaped American deterrence strategy in the 1950s. For Eisenhower, Clausewitz's theoretical "absolute war" illustrated how absurd such a strategy would be in practice. In the nuclear age, Eisenhower saw that logical fantasy as an all too real possibility, and used the prospect of nuclear "absolute war," through the massive retaliation doctrine and the concept of brinkmanship, to deter the Soviet Union and China from risking conflict with the United States.

  In Britain, Clausewitz's influence spread through figures including Spenser Wilkinson, the first Chichele Professor of Military History at Oxford University, and naval historian Julian Corbett (1854-1922), whose work frequently emphasized Clausewitz's ideas about limited objectives and the inherent strengths of the defensive form of war. The Swedish Paradox Development Studio, focused on grand strategy games, named one of their main videogame engines Clausewitz in reference to the Prussian officer, a measure of how far his name has traveled from the battlefields of Jena and Borodino.