The Influence of Sea Power upon History. Alfred Thayer Mahan

      Introductory

       Table of Contents

      The history of Sea Power is largely, though by no means solely, a narrative of contests between nations, of mutual rivalries, of violence frequently culminating in war. The profound influence of sea commerce upon the wealth and strength of countries was clearly seen long before the true principles which governed its growth and prosperity were detected. To secure to one's own people a disproportionate share of such benefits, every effort was made to exclude others, either by the peaceful legislative methods of monopoly or prohibitory regulations, or, when these failed, by direct violence. The clash of interests, the angry feelings roused by conflicting attempts thus to appropriate the larger share, if not the whole, of the advantages of commerce, and of distant unsettled commercial regions, led to wars. On the other hand, wars arising from other causes have been greatly modified in their conduct and issue by the control of the sea. Therefore the history of sea power, while embracing in its broad sweep all that tends to make a people great upon the sea or by the sea, is largely a military history; and it is in this aspect that it will be mainly, though not exclusively, regarded in the following pages.

      A study of the military history of the past, such as this, is enjoined by great military leaders as essential to correct ideas and to the skilful conduct of war in the future. Napoleon names among the campaigns to be studied by the aspiring soldier, those of Alexander, Hannibal, and Caesar, to whom gunpowder was unknown; and there is a substantial agreement among professional writers that, while many of the conditions of war vary from age to age with the progress of weapons, there are certain teachings in the school of history which remain constant, and being, therefore, of universal application, can be elevated to the rank of general principles. For the same reason the study of the sea history of the past will be found instructive, by its illustration of the general principles of maritime war, notwithstanding the great changes that have been brought about in naval weapons by the scientific advances of the past half century, and by the introduction of steam as the motive power.

It is doubly necessary thus to study critically the history and experience of naval warfare in the days of sailing-ships, because while these will be found to afford lessons of present application and value, steam navies have as yet made no history which can be quoted as decisive in its teaching. Of the one we have much experimental knowledge; of the other, practically none. Hence theories about the naval warfare of the future are almost wholly presumptive; and although the attempt has been made to give them a more solid basis by dwelling upon the resemblance between fleets of steamships and fleets of galleys moved by oars, which have a long and well-known history, it will be well not to be carried away by this analogy until it has been thoroughly tested. The resemblance is indeed far from superficial. The feature which the steamer and the galley have in common is the ability to move in any direction independent of the wind. Such a power makes a radical distinction between those classes of vessels and the sailing-ship; for the latter can follow only a limited number of courses when the wind blows, and must remain motionless when it fails. But while it is wise to observe things that are alike, it is also wise to look for things that differ; for when the imagination is carried away by the detection of points of resemblance,--one of the most pleasing of mental pursuits,--it is apt to be impatient of any divergence in its new-found parallels, and so may overlook or refuse to recognize such. Thus the galley and the steamship have in common, though unequally developed, the important characteristic mentioned, but in at least two points they differ; and in an appeal to the history of the galley for lessons as to fighting steamships, the differences as well as the likeness must be kept steadily in view, or false deductions may be made. The motive power of the galley when in use necessarily and rapidly declined, because human strength could not long maintain such exhausting efforts, and consequently tactical movements could continue but for a limited time^[1] ; and again, during the galley period offensive weapons were not only of short range, but were almost wholly confined to hand-to-hand encounter. These two conditions led almost necessarily to a rush upon each other, not, however, without some dexterous attempts to turn or double on the enemy, followed by a hand-to-hand melee. In such a rush and such a melee a great consensus of respectable, even eminent, naval opinion of the present day finds the necessary outcome of modern naval weapons,-- a kind of Donnybrook Fair, in which, as the history of melees shows, it will be hard to know friend from foe. Whatever may prove to be the worth of this opinion, it cannot claim an historical basis in the sole fact that galley and steamship can move at any moment directly upon the enemy, and carry a beak upon their prow, regardless of the points in which galley and steamship differ. As yet this opinion is only a presumption, upon which final judgment may well be deferred until the trial of battle has given further light. Until that time there is room for the opposite view,--that a melee between numerically equal fleets, in which skill is reduced to a minimum, is not the best that can be done with the elaborate and mighty weapons of this age. The surer of himself an admiral is, the finer the tactical development of his fleet, the better his captains, the more reluctant must he necessarily be to enter into a melee with equal forces, in which all these advantages will be thrown away, chance reign supreme, and his fleet he placed on terms of equality with an assemblage of ships which have never before acted together.^[2] History has lessons as to when melees are, or are not, in order.

      The galley, then, has one striking resemblance to the steamer, but differs in other important features which are not so immediately apparent and are therefore less accounted of. In the sailing-ship, on the contrary, the striking feature is the difference between it and the more modern vessel; the points of resemblance, though existing and easy to find, are not so obvious, and therefore are less heeded. This impression is enhanced by the sense of utter weakness in the sailing-ship as compared with the steamer, owing to its dependence upon the wind; forgetting that, as the former fought with its equals, the tactical lessons are valid. The galley was never reduced to impotence by a calm, and hence receives more respect in our day than the sailing-ship; yet the latter displaced it and remained supreme until the utilization of steam. The powers to injure an enemy from a great distance, to manoeuvre for an unlimited length of time without wearing out the men, to devote the greater part of the crew to the offensive weapons instead of to the oar, are common to the sailing vessel and the steamer, and are at least as important, tactically considered, as the power of the galley to move in a calm or against the wind.

      In tracing resemblances there is a tendency not only to overlook points of difference, but to exaggerate points of likeness,--to be fanciful. It may be so considered to point out that as the sailing-ship had guns of long range, with comparatively great penetrative power, and carronades, which were of shorter range but great smashing effect, so the modern steamer has its batteries of long-range guns and of torpedoes, the latter being effective only within a limited distance and then injuring by smashing, while the gun, as of old, aims at penetration. Yet these are distinctly tactical considerations which must affect the plans of admirals and captains; and the analogy is real, not forced. So also both the sailing-ship and the steamer contemplate direct contact with an enemy's vessel,--the former to carry her by boarding, the latter to sink her by ramming; and to both this is the most difficult of their tasks, for to effect it the ship must be carried to a single point of the field of action, whereas projectile weapons may be used from many points of a wide area.

The relative positions of two sailing-ships,