The Influence of Sea Power upon History. Alfred Thayer Mahan
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.
The battle of the Nile, in 1798, was not only an overwhelming victory for the English over the French fleet, but had also the decisive effect of destroying the communications between France and Napoleon's army in Egypt. In the battle itself the English admiral, Nelson, gave a most brilliant example of grand tactics, if that be, as has been defined, "the art of making good combinations preliminary to battles as well as during their progress." The particular tactical combination depended upon a condition now passed away, which was the inability of the lee ships of a fleet at anchor to come to the help of the weather ones before the latter were destroyed; but the principles which underlay the combination, namely, to choose that part of the enemy's order which can least easily be helped, and to attack it with superior forces, has not passed away. The action of Admiral Jervis at Cape St. Vincent, when with fifteen ships he won a victory over twenty-seven, was dictated by the same principle, though in this case the enemy was not at anchor, but under way. Yet men's minds are so constituted that they seem more impressed by the transiency of the conditions than by the undying principle which coped with them. In the strategic effect of Nelson's victory upon the course of the war, on the contrary, the principle involved is not only more easily recognized, but it is at once seen to be applicable to our own day. The issue of the enterprise in Egypt depended upon keeping open the communications with France. The victory of the Nile destroyed the naval force, by which alone the communications could be assured, and determined the final failure; and it is at once seen, not only that the blow was struck in accordance with the principle of striking at the enemy's line of communication, but also that the same principle is valid now, and would be equally so in the days of the galley as of the sailing-ship or steamer.
Nevertheless, a vague feeling of contempt for the past, supposed to be obsolete, combines with natural indolence to blind men even to those permanent strategic lessons which lie close to the surface of naval history. For instance, how many look upon the battle of Trafalgar, the crown of Nelson's glory and the seal of his genius, as other than an isolated event of exceptional grandeur? How many ask themselves the strategic question, "How did the ships come to be just there?" How many realize it to be the final act in a great strategic drama, extending over a year or more, in which two of the greatest leaders that ever lived, Napoleon and Nelson, were pitted against each other? At Trafalgar it was not Villeneuve that failed, but Napoleon that was vanquished; not Nelson that won, but England that was saved; and why? Because Napoleon's combinations failed, and Nelson's intuitions and activity kept the English fleet ever on the track of the enemy, and brought it up in time at the decisive moment.4 The tactics at Trafalgar, while open to criticism in detail, were in their main features conformable to the principles of war, and their audacity was justified as well by the urgency of the case as by the results; but the great lessons of efficiency in preparation, of activity and energy in execution, and of thought and insight on the part of the English leader during the previous months, are strategic lessons, and as such they still remain good.
In these two cases events were worked out to their natural and decisive end. A third may be cited, in which, as no such definite end was reached, an opinion as to what should have been done may be open to dispute. In the war of the American Revolution, France and Spain became allies against England in 1779. The united fleets thrice appeared in the English Channel, once to the number of sixty-six sail of the line, driving the English fleet to seek refuge in its ports because far inferior in numbers. Now, the great aim of Spain was to recover Gibraltar and Jamaica; and to the former end immense efforts both by land and sea were put forth by the allies against that nearly impregnable fortress. They were fruitless. The question suggested-- and it is purely one of naval strategy--is this: Would not Gibraltar have been more surely recovered by controlling the English Channel, attacking the British fleet even in its harbors, and threatening England with annihilation of commerce and invasion at home, than by far greater efforts directed against a distant and very strong outpost of her empire? The English people, from long immunity, were particularly sensitive to fears of invasion, and their great confidence in their fleets, if rudely shaken, would have left them proportionately disheartened. However decided, the question as a point of strategy is fair; and it is proposed in another form by a French officer of the period, who favored directing the great effort on a West India island which might be exchanged against Gibraltar. it is not, however, likely that England would have given up the key of the Mediterranean for any other foreign possession, though she might have yielded it to save her firesides and her capital. Napoleon once said that he would reconquer Pondicherry on the banks of the Vistula. Could he have controlled the English Channel, as the allied fleet did for a moment in 1779, can it be doubted that he would have conquered Gibraltar on the shores of England?
To impress more strongly the truth that history both suggests strategic study and illustrates the principles of war by the facts which it transmits, two more instances will be taken, which are more remote in time than the period specially considered in this work. How did it happen that, in two great contests between the powers of the East and of the West in the Mediterranean, in one of which the empire of the known world was at stake, the opposing fleets met on spots so near each other as Actium and Lepanto? Was this a mere coincidence, or was it due to conditions that recurred, and may recur again?5 If the latter, it is worth while to study out the reason; for if there should again arise a great eastern power of the sea like that of Antony or of Turkey, the strategic questions would be similar. At present, indeed, it seems that the centre of sea power, resting mainly with England and France, is overwhelmingly in the West; but should any chance add to the control of the Black Sea basin, which Russia now has, the possession of the entrance to the Mediterranean, the existing strategic conditions affecting sea power would all be modified. Now, were the West arrayed against the East, England and France would go at once unopposed to the Levant, as they did in 1854, and as England alone went in 1878; in case of the change suggested, the East, as twice before, would meet the West half-way.
At a very conspicuous and momentous period of the world's history, Sea Power had a strategic bearing and weight which has received scant recognition. There cannot now be had the full knowledge necessary for tracing in detail its influence upon the issue of the second Punic War; but the indications which remain are sufficient to warrant the assertion that it was a determining factor. An accurate judgment upon this point cannot be formed by mastering only such facts of the particular contest as have been clearly transmitted, for as usual the naval transactions have been slightingly passed over; there is needed also familiarity with the details of general naval history in order to draw, from slight indications, correct inferences based upon a knowledge of what has been possible at periods whose history is well known. The control of the sea, however real, does not imply that an enemy's single ships or small squadrons cannot steal out of port, cannot cross more or less frequented tracts of ocean, make harassing descents upon unprotected points of a long coast-line, enter blockaded harbors. On the contrary, history has shown that such evasions are always possible, to some extent, to the weaker party, however great the inequality of naval strength. It is not therefore inconsistent with the general control of the sea, or of a decisive part of it, by the Roman fleets, that the Carthaginian admiral Bomilcar in the fourth year of the war, after the stunning