'On War (Volume One)' Summary

Clausewitz argued that war theory cannot be a strict operational advice for generals. Instead, he wanted to highlight general principles that would result from the study of history and logical thinking. He contended that military campaigns could be planned only to a very small degree because incalculable influences or events, so-called friction, would quickly make any too-detailed planning in advance obsolete. Military leaders must be capable to make decisions under time pressure with incomplete information since in his opinion "three quarters of the things on which action is built in war" are concealed and distorted by the fog of war.

In his 1812 Bekenntnisschrift ("Notes of Confession"), he presents a more existential interpretation of war by envisioning war as the highest form of self-assertion by a people. That corresponded in every respect with the spirit of the time when the French Revolution and the conflicts that arose from it had caused the evolution of conscript armies and guerrillas. The people's armies supported the idea that war is an existential struggle.

During the following years, however, Clausewitz gradually abandoned this exalted view and concluded that the war served as a mere instrument: "Thus, war is an act of violence in order to force our will upon the enemy."