THE COMMAND OF THE SEA

We have seen that when two States go to war the primary object of each is to subdue and if possible to destroy the armed forces of the other. Until that is done either completely, or to such an extent as to induce the defeated belligerent to submit, the conflict of wills cannot be determined, and the two States cannot return to those normal relations, involving no violence or force, which constitute a state of peace. If they have a common frontier this circumstance indicates what is, as a general rule, the best and most efficient way of securing the object to be attained. The armed forces of both belligerents lie at the outset within their respective frontiers. If those of either can be constrained by the superior strategy of the other to keep within their own territory, the initial advantage lies with the belligerent who has so constrained them, and the war has in common parlance been carried into the enemy's country. In other words, the invasion of the enemy's territory has begun, and pressure has been brought to bear on his will which, if maintained without intermission and with an intensity duly proportioned to its growing extent, must in the end subdue it. To this there is no alternative. To invade the enemy's territory at all is to inflict a reverse on his armed forces, which would assuredly have prevented the invasion if they could. The territory in the rear of the invading army is in greater or less degree brought under the control of the invader and thereby temporarily lost to the invaded State. If this process is continued the authority and the resources of the invaded State are progressively diminished, until at last when the capital is occupied and the remainder of the invaded country lies open to the advance of the invader, the defeated State must sue for peace on such terms as the invader may concede, because it has nothing left to fight for, and no force wherewithal to fight. This is of course merely an abstract and generalized description of the course of a war on land, but I need not consider its concrete details nor analyse any of the conditions which may, and in the concrete often do, impede or deflect its course, because my sole purpose is to show how armed force operates in the abstract to subdue the will of the belligerent who is worsted in the conflict. It operates by the destruction of his armed forces, by the occupation of his territory, and by the consequent extinction of his authority and appropriation of his resources. He can only recover the latter and liberate his territory by submitting to such terms as the invader may dictate or concede.

Naval warfare aims at the same primary object, namely, the destruction of the enemy's armed forces afloat; but it cannot by itself produce the same decisive effect, because there is no territory which naval force, as such, can occupy and appropriate. The sea is not territory. It is not nor can it be made subject to the authority of an enemy in the same sense that the land can, nor does it possess any resources in itself such as on the land can be appropriated to the disadvantage and ultimate discomfiture of a belligerent whose territory has been invaded. The sea is the common highway of all nations, and the exclusive possession of none. Apart from its fisheries, which, outside the territorial waters of any particular State, are open to all nations, it is of no use, except as a highway, to any State. But its use as a highway is the root of all sea power, the foundation of all naval warfare. It is only by this highway that an island State can be invaded, only by this highway that an island State, or a State having no common frontier with its adversary, can encounter and subdue the armed forces of the enemy, whether on sea or on land.

Moreover, the sea as a highway differs in many important respects from such highways or other lines of communication as serve for the transit and transport of armed forces and their necessary supplies on land. In one sense it is all highway, that is, it can be traversed in every direction by ships, wherever there is water enough for them to float. For military purposes land transit is confined to such highways as are suitable to the march of an army accompanied by artillery and heavy baggage and supply trains, or to such railways as can more expeditiously serve the same purpose. Hence an army advancing in an enemy's country cannot advance on a very broad front, nor can it outmarch its baggage and other supplies except for a very limited time and for some exceptional purpose. Sea transport is subject to no such limitations. Ships carry their own supplies with them, and a fleet of ships, whether of transports or of warships, can move on as broad a front as is compatible with the exercise of due control over their combined movements. Moreover, within certain limits and with certain exceptions, where the waters to be traversed are narrow, ships and fleets can vary their line of transit and advance to such an extent as to render the discovery of their whereabouts a matter of some difficulty. The same conditions affect the transit of such merchant vessels as, carrying the flag of one belligerent, are liable to capture by the other. Hence the primary aim of all naval warfare is and must be so to control the lines of communication which traverse the seas affected, that the enemy cannot move his warships from one point to another without encountering a superior force of his adversary, and that his merchant ships cannot prosecute their voyages without running extreme risk of capture by the way. This is called, in time-honoured phraseology, securing the command of the sea, and the true meaning of this phrase is nothing more nor less than the effective control of all such maritime communications as are or can be affected by the operations of either belligerent. This control may extend, according to circumstances, to all the navigable seas of the globe, or it may be confined, for all practical purposes, to the waters adjacent to the respective territories of the two belligerents. In theory, however, its effect is unlimited, and so it must be in practice, where the territories of one belligerent or the other are widely scattered over the globe. That is the sense in which "the sea is all one."

It is important to note that the phrase "command of the sea" has no definite meaning except in war. In time of peace no State claims to command the sea or to control it in any way. But in any war in which naval force is engaged each belligerent seeks to secure the command of the sea for himself and to deny it to his enemy, that is to close the highway which the sea affords in time of peace to his warships and his merchant vessels alike. As regards the enemy's warships, moreover, he seeks to secure his own command by their destruction or capture. This is not always possible, because if the naval forces of the two belligerents are very unequally matched, it is always open to the weaker of the two to decline the conflict by keeping his main fleets in ports unassailable by naval force alone, and seeking to reduce the superiority of his adversary by assailing him incessantly with torpedo craft. He may also attempt the hazardous enterprise of sending out isolated cruisers to prey upon his adversary's commerce afloat. But in the case supposed, where the superiority of one side is so great as to compel the main fleets of the other to seek the protection of their fortified ports, such an enterprise is, as I shall show in a subsequent chapter, not only extremely hazardous in itself, but quite incapable of inflicting such loss on the superior adversary as would be likely to induce him to abandon the conflict.

Nevertheless the command of the sea is not established, or at best it is only partially, and it may be only temporarily, established by driving the main fleets of the enemy into ports which are inaccessible to naval force alone. They must not only be driven there but compelled to remain there. This has generally been done in the past, and according to many, but not all, naval authorities, it will generally have to be done in the future by the operation known as blockade, whereby the enemy is prevented from coming out, or is compelled if he does come out to fight a superior force lying in wait outside. As a matter of fact, inasmuch as a blockade to be really deterrent must be conducted by a blockading force superior to that which is blockaded—for otherwise the latter need not shun an engagement in the open with the former—it can rarely be the interest of the blockader to prevent the exit of his adversary, since by the hypothesis if he could get him out he could beat him. But the blockade must nevertheless be maintained, because, although the blockaded fleet cannot by that means be destroyed, it can, at any rate, be immobilized and wiped off the board so long as it remains where it is.

The situation in which a blockade is set up by one belligerent and submitted to by the other is not identical with an effective command of the sea, though in certain circumstances it may approximate very closely to it. The blockaded forces may not be so thoroughly intimidated by the superior forces of the blockaders that they could not or would not, if they could, seek a favourable opportunity for breaking or evading the blockade imposed upon them. They may merely be waiting in a position unassailable by naval force alone until the blockading forces are so weakened through incessant torpedo attack, through the wear and tear inflicted on them by the nature of the service on which they are engaged, through stress of weather, through the periodical necessity which compels even the best found ships to withdraw temporarily from the blockade for the purposes of repair, refit, and replenishment of their stores, and through the fatigue imposed on their officers and crews by the incessant vigilance which a blockade requires as to afford them a favourable opportunity of challenging a decision in the open. Or, again, if the forces of the blockaded belligerent are distributed between two or more of his fortified ports, he may attempt an evasion of the blockade at two or more of them for the purpose of combining the forces thus liberated and attacking one or more of the blockading fleets in superior force before they can re-establish their own superiority by concentration. Broadly speaking, this was the plan of operations adopted, or rather attempted, by Napoleon in the memorable campaign which ended at Trafalgar. It was frustrated by the persistent energy of Nelson, by the masterly dispositions of Barham at the Admiralty, by the tenacity with which Cornwallis maintained the blockade at Brest, and by the instinctive sagacity with which other commanders of the several blockading and cruising squadrons nearly always did the right thing at the right moment, divined Barham's purpose, and carried it out almost automatically. Practically, Napoleon was beaten and his projected invasion of England was abandoned many weeks before Trafalgar was won. But the command of the sea was not thereby secured to England. It needed Trafalgar and the destruction of the French and Spanish Fleets there accomplished to effect that consummation. England thenceforth remained in effective and almost undisputed command of the sea, and the Peninsular campaigns of Wellington were for the first time rendered possible. The contrasted phases of the conflict before and after Trafalgar are perhaps the best illustration in history of the vast and vital difference between a command of the sea in dispute and a command of the sea established. Trafalgar was the turning-point in the long conflict between England and Napoleon.