The traditional definition of defense is “warding off a blow” while being in a state of waiting (215). However, there are different variants of defense. Partial combat is defensive in the face of an enemy attack. A battle is defensive when one side waits for the enemy to emerge before one’s position. An entire campaign is defensive when waiting in one’s own theater of war. Offensive actions may take place as part of the defense.

Defensive war is a stronger form than an attack because “[t]o preserve is easier than to acquire” (215). Time may also be on the side of the defense. When the enemy initiates, every combat is defensive. However, defense has a negative objective, which means that it should only be used until a positive objective can be obtained.

In the realm of defense, “numbers, in general, cannot come under consideration” (217). The “three principles of victory” are: attacking from several directions, surprise, and the advantage of controlling ground (271). The latter ranges from natural obstacles to simply being acquainted with the area: “The assistance of ground” usually translates into “a greater influence than ever” on warfare (219).