We must not consider every possibility, but only probabilities.
July 29, 1831, Posen, Prussia (Now Poznan, Poland)
“If I should die, dear Marie,” Carl von Clausewitz wrote to his wife, “that is simply how things are in my profession. Do not grieve too much for a life that had little left to undertake in any event....I cannot say how great is my contempt for human judgment in leaving this world.”1 Three aspects of Clausewitz’s personality reveal themselves here, all constants in his adult life: frustration with the political situation of his time, melancholy (occasionally tinged with fatalism), and his abiding love for his wife.
The year before Clausewitz wrote his note, revolution and riot had engulfed much of Europe. The French ousted Charles X, the brother of the king they had guillotined in January 1793. Uprisings erupted in Germany, Italy, and Spain. The Belgians rose against the Dutch, the Poles against the Russians. It was the latter that brought Clausewitz to Posen as the chief of staff of the Prussian forces posted on an unstable frontier. Across the border, the Russian army fought the hapless Poles.
Eighteen-thirty was the year of revolution. Eighteen-thirty-one was the year of cholera. Clausewitz’s fatalism proved prescient. The disease didn’t take him immediately, but it did take him, on November 16, 1831. On August 23 it had claimed his longtime friend and mentor, the Prussian field marshal August von Gneisenau. The philosopher Hegel succumbed two days before Clausewitz. On June 31 it had killed Field Marshal Hans Karl von Diebitsch, the commander of the Russian army suppressing the Poles; Clausewitz had served under him in 1812. Tens of thousands more joined them as the epidemic burned its way from Asia, to Europe, then to the New World.
Clausewitz left only a deeply bereaved Marie, their union having produced no heirs, which always pained them. But Marie, an intelligent and exceedingly well-read woman—discussions of literature and art sprinkle their correspondence—played an indispensable role in creating a different kind of legacy for her husband. In the spring of 1830 Clausewitz had transferred to the artillery from his post as director of Prussia’s War College. Knowing he would no longer have time for scholarly pursuits, Marie wrote later, “he arranged his papers, sealed them in individual packages, gave each one a label, and bid a sad farewell to this activity, which he held so dear.”2 The bundles contained a number of works, among them histories of the Napoleonic campaigns of 1806, 1812, 1814, and 1815. One held a manuscript titled Vom Kriege, known to the English-speaking world as On War.
After her husband’s death, Marie worked with Major Franz August O’Etzel, who taught military geography at the War College, and her brother, Major General Friedrich Wilhelm von Brühl, to organize Clausewitz’s works. The ten volumes appeared from 1832 to 1837. On War encompassed the first three (1832–1834). The Berlin publisher Ferdinand Dümmler, like Clausewitz a veteran of what the Prussians called the Wars of Liberation (1813–1815), printed the texts, accompanied by maps drawn by O’Etzel. The firm has remained Clausewitz’s publisher since.3
Initially, On War caused only a small tremor in its narrow literary circle. The author of an 1832 review in a military journal judged it tough going, though worth the slog. Its “crystalline waters stream over particles of pure gold,” he wrote. In other words, one had to study the book—not merely read it—to grasp its merit. The work failed to impress Baron Antoine-Henri Jomini—the most important military theorist of the day—who branded it “too pretentious for a didactic discussion” due to its lack of clarity. He grudgingly admitted to pulling an occasional nugget from it, but criticized Clausewitz for being overly skeptical of established military theory.4
Nearly two centuries later, few beyond a narrow band of scholars and hobbyists read Jomini’s works, which is unfortunate, as he has much interesting and useful to say. Clausewitz, in contrast, has become a global brand, one constantly refreshed by a flow of books and articles debating his ideas. All or part of On War appears in an array of translations from Arabic to Vietnamese. Military staff colleges the world over assign Clausewitz’s text, largely to prepare their officers for staff positions and higher command. The Economist magazine titled its defense blog “Clausewitz.”
On War is not without critics. Sir Basil Liddell Hart, the British soldier and theorist, branded Clausewitz the “evil genius of military thought” while blaming his work and its devotees for the slaughter of the First World War’s Western Front. Others have attacked his grandiosity. In the mold of Thucydides, Clausewitz determined to write a book on war that would not be soon forgotten, claiming that readers of the first six books of On War “may even find they contain the basic ideas that might bring about a revolution in the study of war.”5
Clausewitz’s work has certainly not been forgotten. Far from it. The question is, how did it come to be written? That is what this book will seek to answer.