Such a defense can never succeed, for the reason that the recipient is reduced progressively in power of resistance as the attacks follow each other, while the attacker remains in unimpaired vigor, except for the gently depressing influence of fatigue.

Reference to Table I will render this point clear, if we make the progressive reductions of the power of one contestant, and no reductions of the power of the other contestant.
Defensive operations, therefore, include "hitting back"; that is, a certain measure of offensive operations, intended to weaken the ability of the enemy to do damage.

In fact, no operations are more aggressively offensive, or more productive of damage to the enemy's personnel and material, than operations that are carried on in order to defend something.

No animal is so aggressively belligerent as a female "defending" her young.
Offensive and defensive operations are nevertheless quite different, especially in two particulars, one being the use of the initiative or attack, and the other the distance to the home.

In offensive operations, the attack is made; in defensive operations, the attack is resisted; and even if the resistance takes an aggressive character, and drives the original attacker back to the place he started from, yet the side which has made the original attack has carried on offensive operations, and the other side defensive.