Mahan on naval warfare

by A. T. Mahan

Offense therefore dominates, but it does not exclude. The necessity for defense remains obligatory, though subordinate. The two are complementary. It is only in the reversal of rôles, by which priority of importance is assigned to the defensive, that ultimate defeat is involved. Nor is this all. Though opposed in idea and separable in method of action, circumstances not infrequently have permitted the union of the two in a single general plan of campaign, which protects at the same time that it attacks. “Fitz James’s blade was sword and shield.” Of this the system of blockades by the British Navy during the Napoleonic wars was a marked example. Thrust up against the ports of France, and lining her coasts, they covered—shielded—the operations of their own commerce and cruisers in every sea; while at the same time, crossing swords, as it were, with the fleets within, ever on guard, ready to attack, should the enemy give an opening by quitting the shelter of his ports, they frustrated his efforts at a combination of his squadrons by which alone he could hope to reverse conditions. All this was defensive; but the same operation cut the sinews of the enemy’s power by depriving him of sea-borne commerce, and promoted the reduction of his colonies. Both these were measures of offense; and both, it may be added, were directed upon the national communications, the sources of national well-being. The means was one, the effect twofold....

[It is shown that, in the case of insular states, offense and defense are often closely combined, home security depending on control of the sea assured by offensive action of the national fleet.—Editor.]

An insular state, which alone can be purely maritime, therefore contemplates war from a position of antecedent probable superiority from the twofold concentration of its policy; defense and offense being closely identified, and energy, if exerted judiciously, being fixed upon the increase of naval force to the clear subordination of that more narrowly styled military. The conditions tend to minimize the division of effort between offensive and defensive, purpose, and, by greater comparative development of the fleet, to supply a larger margin of disposable numbers in order to constitute a mobile superiority at a particular point of the general field. Such a decisive local superiority at the critical point of action is the chief end of the military art, alike in tactics and strategy. Hence it is clear that an insular state, if attentive to the conditions that should dictate its policy, is inevitably led to possess a superiority in that particular kind of force, the mobility of which enables it most readily to project its power to the more distant quarters of the earth, and also to change its point of application at will with unequalled rapidity.

The general considerations that have been advanced concern all the great European nations, in so far as they look outside their own continent, and to maritime expansion, for the extension of national influence and power; but the effect upon the action of each differs necessarily according to their several conditions. The problem of sea-defense, for instance, relates primarily to the protection of the national commerce everywhere, and specifically as it draws near the home ports; serious attack upon the coast, or upon the ports themselves, being a secondary consideration, because little likely to befall a nation able to extend its power far enough to sea to protect its merchant ships. From this point of view the position of Germany is embarrassed at once by the fact that she has, as regards the world at large, but one coast-line. To and from this all her sea commerce must go; either passing the English Channel, flanked for three hundred miles by France on the one side and England on the other, or else going north about by the Orkneys, a most inconvenient circuit, and obtaining but imperfect shelter from recourse to this deflected route. Holland, in her ancient wars with England, when the two were fairly matched in point of numbers, had dire experience of this false position, though her navy was little inferior in numbers to that of her opponent. This is another exemplification of the truth that distance is a factor equivalent to a certain number of ships. Sea-defense for Germany, in case of war with France or England, means established naval predominance at least in the North Sea; nor can it be considered complete unless extended through the Channel and as far as Great Britain will have to project hers into the Atlantic. This is Germany’s initial disadvantage of position, to be overcome only by adequate superiority of numbers; and it receives little compensation from the security of her Baltic trade, and the facility for closing that sea to her enemies. In fact, Great Britain, whose North Sea trade is but one-fourth of her total, lies to Germany as Ireland does to Great Britain, flanking both routes to the Atlantic; but the great development of the British sea-coast, its numerous ports and ample internal communications, strengthen that element of sea-defense which consists in abundant access to harbors of refuge.

For the Baltic Powers, which comprise all the maritime States east of Germany, the commercial drawback of the Orkney route is a little less than for Hamburg and Bremen, in that the exit from the Baltic is nearly equidistant from the north and south extremities of England; nevertheless the excess in distance over the Channel route remains very considerable. The initial naval disadvantage is in no wise diminished. For all the communities east of the Straits of Dover it remains true that in war commerce is paralyzed, and all the resultant consequences of impaired national strength entailed, unless decisive control of the North Sea is established. That effected, there is security for commerce by the northern passage; but this alone is mere defense. Offense, exerted anywhere on the globe, requires a surplusage of force, over that required to hold the North Sea, sufficient to extend and maintain itself west of the British Islands. In case of war with either of the Channel Powers, this means, as between the two opponents, that the eastern belligerent has to guard a long line of communications, and maintain distant positions, against an antagonist resting on a central position, with interior lines, able to strike at choice at either wing of the enemy’s extended front. The relation which the English Channel, with its branch the Irish Sea, bears to the North Sea and the Atlantic—that of an interior position—is the same which the Mediterranean bears to the Atlantic and the Indian Sea; nor is it merely fanciful to trace in the passage round the north of Scotland an analogy to that by the Cape of Good Hope. It is a reproduction in miniature. The conditions are similar, the scale different. What the one is to a war whose scene is the north of Europe, the other is to operations by European Powers in Eastern Asia.

To protract such a situation is intolerable to the purse and morale of the belligerent who has the disadvantage of position. This of course leads us straight back to the fundamental principles of all naval war, namely, that defense is ensured only by offense, and that the one decisive objective of the offensive is the enemy’s organized force, his battle fleet. Therefore, in the event of a war between one of the Channel Powers, and one or more of those to the eastward, the control of the North Sea must be at once decided. For the eastern State it is a matter of obvious immediate necessity, of commercial self-preservation. For the western State the offensive motive is equally imperative; but for Great Britain there is defensive need as well. Her Empire imposes such a development of naval force as makes it economically impracticable to maintain an army as large as those of the Continent. Security against invasion depends therefore upon the fleet. Postponing more distant interests, she must here concentrate an indisputable superiority. It is, however, inconceivable that against any one Power Great Britain should not be able here to exert from the first a preponderance which would effectually cover all her remoter possessions. Only an economical decadence, which would of itself destroy her position among nations, could bring her so to forego the initial advantage she has, in the fact that for her offense and defense meet and are fulfilled in one factor, the command of the sea. History has conclusively demonstrated the inability of a state with even a single continental frontier to compete in naval development with one that is insular, although of smaller population and resources. A coalition of Powers may indeed affect the balance. As a rule, however, a single state against a coalition holds the interior position, the concentrated force; and while calculation should rightly take account of possibilities, it should beware of permitting imagination too free sway in presenting its pictures. Were the eastern Powers to combine they might prevent Great Britain’s use of the North Sea for the safe passage of her merchant shipping; but even so she would but lose commercially the whole of a trade, the greater part of which disappears by the mere fact of war. Invasion is not possible, unless her fleet can be wholly disabled from appearing in that sea. From her geographical position, she still holds her gates open to the outer world, which maintains three fourths of her commerce in peace.

37. Bearing of Political Developments on Naval Policy and Strategy[^[115]]

The external activities of Europe, noted a dozen years ago and before, have now to a certain extent been again superseded by rivalries within Europe itself. Those rivalries, however, are the result of their previous external activities, and in the last analysis they depend upon German commercial development. This has stimulated the German Empire to a prodigious naval programme, which affects the whole of Europe and may affect the United States. In 1897 I summed up two conspicuous European conditions as being the equilibrium then existing between France and Germany, with their respective allies, and the withdrawal of Great Britain from active association with the affairs of the Continent. At that date the Triple Alliance, Austria, Germany, Italy, stood against the Dual Alliance, France and Russia; Great Britain apart from both, but with elements of antagonism against Russia and France, and not against the German monarchies or Italy. These antagonisms arose wholly from conditions external to Europe,—in India against Russia, and in Africa against France. Later, the paralysis of Russia, through her defeat by Japan, and through her internal troubles, left France alone for a time; during which Germany, thus assured against land attack, was better able to devote much money to the fleet, as the protector of her growing commerce. The results have been a projected huge German navy, and a German altercation with France relative to Moroccan affairs; incidents which have aroused Great Britain to a sense of naval danger, and have propelled her to the understandings—whatever they amount to—with France and Russia, which we now know as the Triple Entente. In short, Great Britain has abandoned the isolation of twenty years ago, stands joined to the Dual Alliance, and it becomes a Triple Entente.

To the United States this means that Great Britain, once our chief opponent in matters covered by the Monroe Doctrine, but later by the logic of events drawn to recede from that opposition, so that she practically backed us against Europe in 1898, and subsequently conceded the Panama arrangement known as the Hay-Pauncefote Treaty, cannot at present count for as much as she did in naval questions throughout the world. It means to the United States and to Japan that Great Britain has too much at stake at home to side with the one or the other, granting she so wished, except as bound by treaty, which implies reciprocal obligations. Between her and Japan such specific obligations exist. They do not in the case of the United States; and the question whether the two countries are disposed to support one another, and, if so, to what extent, or what the attitude of Great Britain would be in case of difficulty between Japan and the United States, are questions directly affecting naval strategy.[^[116]]

Great Britain does indeed for the moment hold Germany so far in check that the German Empire also can do no more than look after its European interests; but should a naval disaster befall Great Britain, leaving Germany master of the naval situation, the world would see again a predominant fleet backed by a predominant army, and that in the hands, not of a state satiated with colonial possessions, as Great Britain is, but of one whose late entry into world conditions leaves her without any such possessions at all of any great value. The habit of mind is narrow which fails to see that a navy such as Germany is now building will be efficacious for other ends than those immediately proposed. The existence of such a fleet is a constant factor in contemporary politics; the part which it shall play depending upon circumstances not always to be foreseen. Although the colonial ambitions of Germany are held in abeyance for the moment, the wish cannot but exist to expand her territory by foreign acquisitions, to establish external bases for the support of commercial or political interests, to build up such kindred communities as now help to constitute the British Empire, homes for emigrants, markets for industries, sources of supplies of raw materials, needed by those industries.