War, or the battles between armies from opposing states, “is a matter of life and death, a road either to safety or to ruin” (1.2). Success in war depends on careful attention to all factors in the field, including weather, terrain, enemy strengths and weaknesses, good intelligence from spies and informants, and, vitally, the leadership qualities of the generals and the king. Wars are costly in resources and lives, and they should be conducted quickly, efficiently, and never wantonly, especially against superior forces. After thorough planning, leaders must make sure their own forces are impregnable, keep them hidden until the moment of battle, and attack only as diversions or in full force against the enemy’s weak spots. 

Strategy is the general plan for war. It includes basic battle principles such as an unassailable defense and a crushing offense against an enemy’s weakest points. Strategy involves careful preparation of battle plans along with marshaling, organizing, and supplying the army. High-level strategic thinking is fairly straightforward, but few people are able to maintain the cool logic required to sustain the overall plan during the vagaries of battle: “All men can see the tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved” (6.