For a quarter-century various allied coalitions struggled to contain and defeat revolutionary France and Napoleon, and Clausewitz witnessed many aspects of this dynamic period of history. At the heart of Clausewitz's life work on military theory was understanding Napoleonic warfare---what made French, and in particular, Napoleon’s armies so successful on the battlefield? He was not, however, a blind follower of the Emperor; he devotes a whole chapter and many passages of On War to criticizing Napoleon, especially his strategic decisions.
Clausewitz believed in the historical specificity of warfare which fundamentally clashed with his desire to produce a universal theory of war. To Clausewitz, writing in the early decades of the nineteenth century, it appeared that Napoleonic warfare was sweeping traditional warfare away in one great revolutionary torrent. (It is interesting to note the similarities to today, with post-9/11 wars seeming to sweep away late twentieth century U.S. military theory and doctrine.)
Napoleon’s campaigns and French revolutionary warfare---focusing here on mobilization and employment of conscripted mass formations---infused much of Clausewitz’s theories. Clausewitz’s central theory of the remarkable trinity---of people, government, and military---was (or can be seen as) a direct attempt to explain the unusual mixture of forces to come out of revolutionary France. According to Ian Roxborough, "Napoleonic warfare enabled each element of Clausewitz's trinity to achieve full development: the elemental energies of a mobilized populace, the clarity and simplicity of state policy using war as an instrument of politics, and the genius of the commander, able to deliver decisive results by destruction of the enemy's armies." Clausewitz was focused on the seemingly absolute nature of warfare unleashed first during the French Revolutionary wars, then the Napoleonic wars, though he knew that the inherent limiting forces (that kept war from its absolute expression) were still present at all times. The question for him was what was unique about warfare, 1789-1815, that pushed it toward the absolute pole of the spectrum?
A lot has been made already in scholarly works about the impact of Kantian philosophical methods and the Hegelian dialectical approach evident in Clausewitz’s theory of war, and it is hard to deny strong German anti-enlightenment influences in his writings. Interestingly enough, Clausewitz can be seen himself as a synthesis of a larger historical dynamic. Clausewitz inherited Enlightenment ideas, intellectual tools, but was clearly also not a product of the Enlightenment. The Enlightenment and its drive to create a unified science of man and human experience can be seen as the thesis. The hyper-passionate wars of the French Revolution and Napoleon can be seen as the antithesis to the Enlightenment. Then Clausewitz can be seen as the synthesis between the two, though he never finished his life's work.
In many ways, Clausewitz was trying to understand---not as a historian, but as a theoretician---how the revolutionary forms of warfare of his lifetime developed out of the rational warfare of the earlier period--the period associated with Frederick the Great. "From the Enlightenment [Clausewitz] inherited his empiricism, skepticism, and taxonomic ingenuity. But he was totally opposed to the ideal of creating a theory of war. In his eyes, the Napoleonic theorists had replaced Frederician dogma with new dogmas, ones whose general use was just as invalid as Frederick's had proved." Clausewitz was obviously impressed by the dramatic nature of changes to warfare in his lifetime but also recognized the contingent nature of contemporary war and Napoleonic warfare, in particular. Evincing his historical bent, he saw a long history of warfare preceding the revolutionary-Napoleonic era, and paid special attention to this older body of evidence (I surmise) as a check against the fast changing characteristics of warfare in his lifetime.
Clausewitz witnessed the politicization of warfare---the revolutionary zeal of French units beginning in 1792 was really revolutionary, even if their organization, weaponry, and tactics were less so than is sometimes argued---which prompted Clausewitz to grapple with war's fundamental political nature. In other words, Clausewitz was looking at war through a political lens because the political side of war’s nature was so prevalent during his lifetime.
There is another key connection between Clausewitz and Napoleon. Napoleonic tactics were almost all developed or at least outlined in military writings prior to Napoleon’s arrival on the scene---Napoleon was an innovator in applying ideas of others as opposed to being an originator of new ideas himself. But Napoleon probably did develop operational art---properly speaking---the linking together of battles and other engagements to achieve strategic war aims---another way of saying make tactical operations serve the political purpose of war. Clausewitz, to fully develop his political theory of war, needed to understand how tactical actions connected with strategy. Clausewitz's review of Napoleonic warfare made this---the connections between tactics, operations (what Napoleon was revolutionizing through the exploitation of the division-corps system), and strategy---much more evident to him. Clausewitz probably did not live long enough to flesh out more the three levels of war that we take for granted today, and that underpin all western military doctrine. That would have to wait for another century and the Soviet theorists of the inter-war period.
1. Ian Roxborough, “Clausewitz and the Sociology of War,” The British Journal of Sociology 45, no. 4 (December 1994): 628.
2. Garry Wills, “Critical Inquiry ("Kritik") in Clausewitz,” Critical Inquiry 9, no. 2 (December 1982): 299.