Communications dominate war; broadly considered, they are the most important single element in strategy, political or military. In its control over them has lain the pre-eminence of sea power—as an influence upon the history of the past; and in this it will continue, for the attribute is inseparable from its existence. This is evident because, for reasons previously explained, transit in large quantities and for great distances is decisively more easy and copious by water than by land. The sea, therefore, is the great medium of communications—of commerce. The very sound, “commerce,” brings with it a suggestion of the sea, for it is maritime commerce that has in all ages been most fruitful of wealth; and wealth is but the concrete expression of a nation’s energy of life, material and mental. The power, therefore, to insure these communications to one’s self, and to interrupt them for an adversary, affects the very root of a nation’s vigor, as in military operations it does the existence of an army, or as the free access to rain and sun—communication from without—does the life of a plant. This is the prerogative of the sea powers; and this chiefly—if not, indeed, this alone—they have to set off against the disadvantage of position and of numbers under which, with reference to land power, they labor in Asia. It is enough. Pressure afar off—diversion—is adequate to relieve that near at hand, as Napoleon expected to conquer Pondicherry on the banks of the Vistula. But if the sea powers embrace the proposition that has found favor in America, and, by the concession of immunity to an enemy’s commerce in time of war, surrender their control of maritime communications, they will have abdicated the scepter of the sea, for they will have abandoned one chief means by which pressure in one quarter—the sea—balances pressure in a remote and otherwise inaccessible quarter. Never was moment for such abandonment less propitious than the present, when the determination of influence in Asia is at stake. 8. OFFENSIVE OPERATIONS[27] [The situation here considered is that of a fleet that has driven the enemy from a base in the theater of war, but has still to cope with the enemy fleet falling back on another base.—EDITOR.]