The definite object proposed in this work is an examination of the general history of Europe and America with particular reference to the effect of sea power upon the course of that history. Historians generally have been unfamiliar with the conditions of the sea, having as to it neither special interest nor special knowledge; and the profound determining influence of maritime strength upon great issues has consequently been overlooked. This is even more true of particular occasions than of the general tendency of sea power. It is easy to say in a general way, that the use and control of the sea is and has been a great factor in the history of the world; it is more troublesome to seek out and show its exact bearing at a particular juncture. Yet, unless this be done, the acknowledgment of general importance remains vague and unsubstantial; not resting, as it should, upon a collection of special instances in which the precise effect has been made clear, by an analysis of the conditions at the given moments.
A curious exemplification of this tendency to slight the bearing of maritime power upon events may be drawn from two writers of that English nation which more than any other has owed its greatness to the sea. "Twice," says Arnold in his History of Rome, "has there been witnessed the struggle of the highest individual genius against the resources and institutions of a great nation, and in both cases the nation was victorious. For seventeen years Hannibal strove against Rome, for sixteen years Napoleon strove against England; the efforts of the first ended in Zama, those of the second in Waterloo." Sir Edward Creasy, quoting this, adds: "One point, however, of the similitude between the two wars has scarcely been adequately dwelt on; that is, the remarkable parallel between the Roman general who finally defeated the great Carthaginian, and the English general who gave the last deadly overthrow to the French emperor. Scipio and Wellington both held for many years commands of high importance, but distant from the main theatres of warfare. The same country was the scene of the principal military career of each. It was in Spain that Scipio, like Wellington, successively encountered and overthrew nearly all the subordinate generals of the enemy before being opposed to the chief champion and conqueror himself. Both Scipio and Wellington restored their countrymen's confidence in arms when shaken by a series of reverses, and each of them closed a long and perilous war by a complete and overwhelming defeat of the chosen leader and the chosen veterans of the foe."
Neither of these Englishmen mentions the yet more striking coincidence, that in both cases the mastery of the sea rested with the victor. The Roman control of the water forced Hannibal to that long, perilous march through Gaul in which more than half his veteran troops wasted away; it enabled the elder Scipio, while sending his army from the Rhone on to Spain, to intercept Hannibal's communications, to return in person and face the invader at the Trebia. Throughout the war the legions passed by water, unmolested and un-wearied, between Spain, which was Hannibal's base, and Italy, while the issue of the decisive battle of the Metaurus, hinging as it did upon the interior position of the Roman armies with reference to the forces of Hasdrubal and Hannibal, was ultimately due to the fact that the younger brother could not bring his succoring reinforcements by sea, but only by the land route through Gaul. Hence at the critical moment the two Carthaginian armies were separated by the length of Italy, and one was destroyed by the combined action of the Roman generals.
On the other hand, naval historians have troubled themselves little about the connection between general history and their own particular topic, limiting themselves generally to the duty of simple chroniclers of naval occurrences. This is less true of the French than of the English; the genius and training of the former people leading them to more careful inquiry into the causes of particular results and the mutual relation of events.
There is not, however, within the knowledge of the author any work that professes the particular object here sought; namely, an estimate of the effect of sea power upon the course of history and the prosperity of nations. As other histories deal with the wars, politics, social and economical conditions of countries, touching upon maritime matters only incidentally and generally unsympathetically, so the present work aims at putting maritime interests in the foreground, without divorcing them, however, from their surroundings of cause and effect in general history, but seeking to show how they modified the latter, and were modified by them.
The period embraced is from 1660, when the sailing ship era, with its distinctive features, had fairly begun, to 1783, the end of the American Revolution. While the thread of general history upon which the successive maritime events is strung is intentionally slight, the effort has been to present a clear as well as accurate outline. Writing as a naval officer in full sympathy with his profession, the author has not hesitated to digress freely on questions of naval policy, strategy, and tactics; but as technical language has been avoided, it is hoped that these matters, simply presented, will be found of interest to the unprofessional reader.
A. T. MAHAN
DECEMBER, 1889.
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, or fleets, with reference to the direction of the wind involved most important tactical questions, and were perhaps the chief care of the seamen of that age. To a superficial glance it may appear that since this has become a matter of such indifference to the steamer, no analogies to it are to be found in present conditions, and the lessons of history in this respect are valueless. A more careful consideration of the distinguishing characteristics of the lee and the weather "gage,"[3] directed to their essential features and disregarding secondary details, will show that this is a mistake. The distinguishing feature of the weather-gage was that it conferred the power of giving or refusing battle at will, which in turn carries the usual advantage of an offensive attitude in the choice of the method of attack. This advantage was accompanied by certain drawbacks, such as irregularity introduced into the order, exposure to raking or enfilading cannonade, and the sacrifice of part or all of the artillery-fire of the assailant,--all which were incurred in approaching the enemy. The ship, or fleet, with the lee-gage could not attack; if it did not wish to retreat, its action was confined to the defensive, and to receiving battle on the enemy's terms. This disadvantage was compensated by the comparative ease of maintaining the order of battle undisturbed, and by a sustained artillery-fire to which the enemy for a time was unable to reply. Historically, these favorable and unfavorable characteristics have their counterpart and analogy in the offensive and defensive operations of all ages. The offence undertakes certain risks and disadvantages in order to reach and destroy the enemy; the defence, so long as it remains such, refuses the risks of advance, holds on to a careful, well-ordered position, and avails itself of the exposure to which the assailant submits himself. These radical differences between the weather and the lee gage were so clearly recognized, through the cloud of lesser details accompanying them, that the former was ordinarily chosen by the English, because their steady policy was to assail and destroy their enemy; whereas the French sought the lee-gage, because by so doing they were usually able to cripple the enemy as he approached, and thus evade decisive encounters and preserve their ships. The French, with rare exceptions, subordinated the action of the navy to other military considerations, grudged the money spent upon it, and therefore sought to economize their fleet by assuming a defensive position and limiting its efforts to the repelling of assaults. For this course the lee-gage, skilfully used, was admirably adapted so long as an enemy displayed more courage than conduct; but when Rodney showed an intention to use the advantage of the wind, not merely to attack, but to make a formidable concentration on a part of the enemy's line, his wary opponent, De Guichen, changed his tactics. In the first of their three actions the Frenchman took the lee. gage; but after recognizing Rodney's purpose he manoeuvred for the advantage of the wind, not to attack, but to refuse action except on his own terms. The power to assume the offensive, or to refuse battle, rests no longer with the wind, but with the party which has the greater speed; which in a fleet will depend not only upon the speed of the individual ships, but also upon their tactical uniformity of action. Henceforth the ships which have the greatest speed will have the weather-gage.
It is not therefore a vain expectation, as many think, to look for useful lessons in the history of sailing-ships as well as in that of galleys. Both have their points of resemblance to the modern ship; both have also points of essential difference, which make it impossible to cite their experiences or modes of action as tactical _precedents_ to be followed. But a precedent is different from and less valuable than a principle. The former may be originally faulty, or may cease to apply through change of circumstances; the latter has its root in the essential nature of things, and, however various its application as conditions change, remains a standard to which action must conform to attain success. War has such principles; their existence is detected by the study of the past, which reveals them in successes and in failures, the same from age to age. Conditions and weapons change; but to cope with the one or successfully wield the others, respect must be had to these constant teachings of history in the tactics of the battlefield, or in those wider operations of war which are comprised under the name of strategy.
It is however in these wider operations, which embrace a whole theatre of war, and in a maritime contest may cover a large portion of the globe, that the teachings of history have a more evident and permanent value, because the conditions remain more permanent. The theatre of war may be larger or smaller, its difficulties more or less pronounced, the contending armies more or less great, the necessary movements more or less easy, but these are simply differences of scale, of degree, not of kind. As a wilderness gives place to civilization, as means of communication multiply, as roads are opened, rivers bridged, food-resources increased, the operations of war become easier, more rapid, more extensive; but the principles to which they must be conformed remain the same. When the march on foot was replaced by carrying troops in coaches, when the latter in turn gave place to railroads, the scale of distances was increased, or, if you will, the scale of time diminished; but the principles which dictated the point at which the army should be concentrated, the direction in which it should move, the part of the enemy's position which it should assail, the protection of communications, were not altered. So, on the sea, the advance from the galley timidly creeping from port to port to the sailing-ship launching out boldly to the ends of the earth, and from the latter to the steamship of our own time, has increased the scope and the rapidity of naval operations without necessarily changing the principles which should direct them; and the speech of Hermocrates twenty-three hundred years ago, before quoted, contained a correct strategic plan, which is as applicable in its principles now as it was then. Before hostile armies or fleets are brought into contact (a word which perhaps better than any other indicates the dividing line between tactics and strategy), there are a number of questions to be decided, covering the whole plan of operations throughout the theatre of war. Among these are the proper function of the navy in the war; its true objective; the point or points upon which it should be concentrated; the establishment of depots of coal and supplies; the maintenance of communications between these depots and the home base; the military value of commerce-destroying as a decisive or a secondary operation of war; the system upon which commerce-destroying can be most efficiently conducted, whether by scattered cruisers or by holding in force some vital centre through which commercial shipping must pass. All these are strategic questions, and upon all these history has a great deal to say. There has been of late a valuable discussion in English naval circles as to the comparative merits of the policies of two great English admirals, Lord Howe and Lord St. Vincent, in the disposition of the English navy when at war with France. The question is purely strategic, and is not of mere historical interest; it is of vital importance now, and the principles upon which its decision rests are the same now as then. St. Vincent's policy saved England from invasion, and in the hands of Nelson and his brother admirals led straight up to Trafalgar.
It is then particularly in the field of naval strategy that the teachings of the past have a value which is in no degree lessened. They are there useful not only as illustrative of principles, but also as precedents, owing to the comparative permanence of the conditions. This is less obviously true as to tactics, when the fleets come into collision at the point to which strategic considerations have brought them. The unresting progress of mankind causes continual change in the weapons; and with that must come a continual change in the manner of fighting,--in the handling and disposition of troops or ships on the battlefield. Hence arises a tendency on the part of many connected with maritime matters to think that no advantage is to be gained from the study of former experiences; that time so used is wasted. This view, though natural, not only leaves wholly out of sight those broad strategic considerations which lead nations to put fleets afloat, which direct the sphere of their action, and so have modified and will continue to modify the history of the world, but is one-sided and narrow even as to tactics. The battles of the past succeeded or failed according as they were fought in conformity with the principles of war; and the seaman who carefully studies the causes of success or failure will not only detect and gradually assimilate these principles, but will also acquire increased aptitude in applying them to the tactical use of the ships and weapons of his own day. He will observe also that changes of tactics have not only taken place after changes in weapons, which necessarily is the case, but that the interval between such changes has been unduly long. This doubtless arises from the fact that an improvement of weapons is due to the energy of one or two men, while changes in tactics have to overcome the inertia of a conservative class; but it is a great evil. It can be remedied only by a candid recognition of each change, by careful study of the powers and limitations of the new ship or weapon, and by a consequent adaptation of the method of using it to the qualities it possesses, which will constitute its tactics. History shows that it is vain to hope that military men generally will be at the pains to do this, but that the one who does will go into battle with a great advantage,--a lesson in itself of no mean value.
We may therefore accept now the words of a French tactician, Morogues, who wrote a century and a quarter ago: "Naval tactics are based upon conditions the chief causes of which, namely the arms, may change; which in turn causes necessarily a change in the construction of ships, in the manner of handling them, and so finally in the disposition and handling of fleets." His further statement, that "it is not a science founded upon principles absolutely invariable," is more open to criticism. It would be more correct to say that the application of its principles varies as the weapons change. The application of the principles doubtless varies also in strategy from time to time, but the variation is far less; and hence the recognition of the underlying principle is easier. This statement is of sufficient importance to our subject to receive some illustrations from historical events.