The main advantage of superior speed in naval operations is the ability it gives to secure tactical positions of advantage, and to make desirable strategic dispositions; ability, for instance, to T or flank an enemy force, and to prevent the enemy from T-ing or flanking; also to catch separated parts of an enemy fleet before they can unite, while retaining the ability to divide one’s own force without undue risk.  For these purposes, speed is an element of the highest value; but the high price that it costs in gun power or armor protection—­or both—­and the fact that speed cannot always be counted on by reason of possible engine breakdowns and foul bottoms, result in giving to war-ships a lower speed than otherwise they would have.

Owing to the fact that, for any given horse-power put into a ship, the speed attainable increases with her length; and owing to the further fact that the weight that any ship can carry increases more rapidly than the displacement (weight of the ship complete), the best combination of gun power, armor protection, and speed is attainable in the largest ship.  In other words, the larger the ship, the more power it can carry in proportion to its size, and the more quickly that power can be placed where it can do the most good.

Strategic Operations.—­These may be divided into two classes, offensive and defensive.  The two classes are distinct; and yet there is no sharp dividing-line between them any more than there is between two contiguous colors in the spectrum.  Defensive operations of the kind described by a popular interpretation of the word “defense” would be operations limited to warding off or escaping the enemy’s attack, and would be just as efficacious as the passive warding off of the blows of fists.  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.