On War by Carl von Clausewitz

On War, unquestionably the most important single work ever written on the theory of warfare and of strategy, was written by the Prussian military thinker Carl von Clausewitz. Clausewitz is widely acknowledged as the most important of the major strategic theorists. Even though he's been dead for over a century and a half, he remains the most frequently cited, the most controversial, and in many respects the most modern.