Now these policies, especially after a nation has adhered to them for long, seem vital in her eyes, and they usually are so.  To Great Britain, whose major policy is that she must be mistress of the seas, it is vital that she should be.  Her people are surrounded by the ocean, and unless they are willing simply to eke out an agricultural existence, it is essential that she should be able to manufacture articles, send them out in ships to all parts of the world, and receive in return money and the products of other lands.  In order that she may be able to do this, she must feel sure that no power on earth can restrain the peaceful sailing to and fro of her exporting and importing ships.  This assurance can be had only through physical force; it can be exerted only by a navy.  Germany has been gradually coming into the same position, and the same clear comprehension, owing to the increase of her population, the growth of their desire for wealth, and their realization of the control by Great Britain and the United States of large areas of the surface of the earth.  Germany’s determination to break down, at least in part, that overpowering command of the sea which Great Britain wields has been the result.  The ensuing rapid growth and excellence of Germany’s navy and merchant marine brought Germany and England into sharp competition.  Military and naval men have seen for years that these competing nations would have to go to war some day in “self-defense.”

In the minds of some people the idea of what constitutes “defense” is rather hazy, and “defense” is deemed almost synonymous with “resistance.”  Perhaps the clearest idea of what constitutes “defense” is given in a sentence in Webster’s Dictionary, that reads:  “The inmates of a fortress are defended by its guns, protected by its walls, and guarded against surprise by sentries.”

The distinction is important, and the partially aggressive character of defense it indicates is exemplified in all walks of human and brute life.  Any animal, no matter how peaceably inclined, will turn on his aggressor—­unless, indeed, he runs away.  No one ever saw any brute oppose a merely passive resistance to attack.  Every man recognizes in himself an instinct to hit back if he is hit.  If it be an instinct, it must have been implanted in us for a reason; and the reason is not hard to find in the universal law of self-protection, which cannot be satisfied with the ineffectual method of mere parrying or resisting.

Naval defense, like military defense, therefore, is not passive defense only, but contains an element of “offense” as well.  When the defense contains in large measure the element of offense, it is said in military parlance to be “offensive-defensive”; and the most effective defensive is this offensive-defensive.  When a defending force throws off its defensive attitude entirely and advances boldly to attack, it is said to have “assumed the offensive”; but even this assumption, especially if it be temporary—­as when a beleaguered garrison makes a sortie—­does not rob the situation of its defensive character.