CHAPTER V
The condition of disputed command of the sea is the normal condition at the outbreak of any war in which operations at sea are involved between two belligerents of approximately equal strength, or indeed between any two belligerents, the weaker of whom is sufficiently inspired by the animus pugnandi—or it may be by other motives rather political than strategic in character—to try conclusions with his adversary in the open. This follows immediately from the nature of command of the sea, which is, it will be remembered, the effective control over the maritime communications of the waters in dispute. I must here repeat, that the phrase command of the sea has no definite meaning in time of peace. No nation nowadays seeks in time of peace to control maritime communications, that is, to exercise any authority or constraint over any ships, whether warships or merchant vessels—other than those flying its own flag—which traverse the seas on their lawful occasions. There was, indeed, a time when England claimed what was called the "sovereignty of the seas," that is, the right to exact at all times certain marks of deference to her flag, in the form of certain salutes of ceremony, from all ships traversing the seas surrounding the British Islands, the narrow seas as they were called. But that is an entirely different thing from the command of the sea in a strategic sense, and has in fact no connection with it. It has long been abandoned and it need only be mentioned here in order to be carefully distinguished from the latter. Any nation seeking to exercise or secure the command of the sea in this sense would in so doing engage in an act of war, and would be regarded as so engaging by any other nation whose rights and interests were in any way affected by the act. Hence the difference between the two is plain. The claim to the sovereignty of the seas and the exaction of the ceremonial observance—the lowering of a flag or a sail—which symbolized it, was not in itself an act of war, though it might lead to war if the claim were resisted. An attempt to assert or secure the command of the sea is, on the other hand, in itself an act of war and would never be made by any nation not prepared to take the consequence in the instant outbreak of hostilities.
For what is it that a nation seeks to do when it attempts to exercise or secure the command of the sea? It seeks to do nothing more and nothing less than to deny freedom of access to the waters in dispute to the ships, whether warships or merchant ships, of some other nation. It denies the common right of highway, which is the essential attribute of the sea, to that other nation, and seeks to secure the monopoly of that right for itself. In other words, it seeks to drive its adversary's warships from the sea, and either by the capture of his merchant vessels to appropriate the wealth they contain or by destroying them to deprive the adversary of its enjoyment. This is all that naval warfare as such can do. If the enemy is not constrained by the destruction of his warships and the extinction of his maritime commerce to submit to his victorious adversary's will, other agencies, not exclusively naval in character, must be employed to bring about that consummation. This means that military force must be brought into operation, either for the invasion of the defeated adversary's territory or for the occupation of some of his possessions lying across the seas, if he has any. If he has none, or if such as he has are not worth taking or holding—either as a permanent possession or as what is called a material guarantee to be used in the subsequent negotiations for peace—then the only alternative is invasion. But that is a subject which demands a chapter to itself.
It rarely happens, however, that a great naval Power is devoid of transmarine possessions altogether, or that such as it holds are esteemed by it to be of so little value or importance that their seizure by an enemy would leave matters in statu quo. Sea power is, as a rule, the outcome of a flourishing maritime commerce. Maritime commerce as it expands, tends, even apart from direct colonization, to bring territorial occupation in its train. The origin and history of the British rule in India is a signal illustration of this tendency. There are other causes of territorial expansion across the seas, as Admiral Mahan has pointed out in his latest work on Naval Strategy, but it is a rule which admits of no exceptions that territorial possessions across the seas, however they may have been acquired, compel the Power which holds them to develop a navy which, in the last resort, must be capable of defending them. It was not, indeed, the needs of maritime commerce which induced the United States to acquire Puerto Rico and the Philippines. Their acquisition was, as it were, a by-product of victorious sea power. But the vast expansion of the United States Navy which the last dozen years have witnessed is the direct result and the logical consequence of their acquisition.
Applying these principles to the defence of the British Empire we see at once that the command of the sea, in the sense already defined, is essential to its successful prosecution. The case is not merely exceptional, it is absolutely unique. The British Isles might recover from the effects of a successful invasion, as other countries have done in like case. But the destruction of their maritime commerce would ruin them irretrievably, even if no invasion were undertaken. Half the maritime commerce of the world is carried on under the British flag. The whole of that commerce would be suppressed if an enemy once secured the command of the sea. The British Isles would be starved out in a few weeks. Whether an enemy so situated would decide to invade or invest—that is, so to impede our commerce that only an insignificant fraction of it could by evasion reach our ports—is a question not so much of strategy as of the economics of warfare. But really it hardly matters a pin which he decided to do. We should have to submit in either case. What would happen to our Dominions, Dependencies, and Colonies is plain. Those which are defenceless the enemy would seize if he thought it worth his while. In the case supposed they could obtain no military assistance from the mother-country. But those which could defend themselves he would have to overcome, if he could, by fighting. The great Dominions of the Empire would not fall into an enemy's lap merely because he had compelled the United Kingdom to sue for peace. To subdue them by force of arms would be a very formidable undertaking.
Such are the tremendous effects of an adverse command of the sea on an insular kingdom and an oceanic empire, which carries on—not by virtue of any artificial monopoly, but solely by virtue of its hardly won ascendency in the economic struggle for existence—half the maritime commerce of the world. On the other hand, its effects on any nation which does not depend on the sea for its existence can never be so overwhelming and may even be insignificant. Germany was very little affected by the command of the sea enjoyed by France in the War of 1870. But in view of the enormous growth of German maritime commerce in recent years, a superiority of France at sea equal to that which she enjoyed in 1870 would now be a much more serious menace to Germany. In all such cases the issue must be decided by military operations suitable to the circumstances and the occasion—operations in which naval force may take an indispensable part even though it may not directly decide the issue. It was, for example, the United States army that captured Santiago and secured the deliverance of Cuba; but it was the United States Navy alone that enabled the troops to be in Cuba at all and to do what they did there. Again, in the war between Russia and Japan it was the capture of Port Arthur and the final overthrow at Tsu-Shima of all that remained of Russia's effective naval forces that induced Russia to entertain overtures for peace. But the reduction of Port Arthur was mainly the work of the military arm and the continued successes of the Japanese armies in Manchuria must have contributed largely to Russia's surrender. These successes were, it is true, rendered possible by the Japanese Navy alone. It cannot be said that the Japanese ever held the undisputed command of the sea until after Tsu-Shima had been fought and won. But at the very outset of the war they established such an ascendency over the Russian naval forces in Far Eastern waters that the latter were in the end reduced to something less than even a "fortress fleet." At Port Arthur, writes Admiral Mahan, the fleet was "neither a fortress fleet, for except the guns mounted from it, the fleet contributed nothing to the defence of the place; nor yet a fleet in being, for it was never used as such." Its animus pugnandi was fatally depressed on the first night of the war, and finally extinguished after the action of August 10.
The truth is, that in all the larger achievements of sea power—those, that is, to which a combination of naval and military force is indispensable—it is impossible to disengage the influence of one of these factors on the final issue from that of the other, and perhaps idle to attempt do to so. They act, as it were, like a chemical combination, not like the resultant of two separate but correlated mechanical forces, and their joint effect may be just as different from what might be the effect of either acting separately as water is different from the oxygen and hydrogen of which it is composed. But their operation in this wise can only begin after the command of the sea has been secured, or at least has been so far established as to reduce to a negligible quantity the risk of conducting military operations across seas of which the command is still nominally in dispute. Now there are several phases or stages in the enterprise of securing the command of the sea; but they all depend on the power and the will to fight for it. There is no absolute command of the sea, except in the case of hostilities between two belligerents, separated by the sea, one of whom has no naval force at all. The solitary case in history of this situation is that of the War in South Africa. A similar situation would arise if one of two belligerents had completely destroyed all the effective naval force of the other. But that is a situation of which history affords few, if any, examples. Between these two extremes lies the whole history of naval warfare.
There is, moreover, one characteristic of naval warfare which has no exact counterpart in the conduct of military enterprises on land. This is the power which a naval belligerent has of withdrawing his sea-going force out of the reach of the sea-going force of the enemy by placing it in sheltered harbours too strongly fortified for the enemy to reduce by naval power alone. The only effective answer to this which the superior belligerent can make is, as has already been shown, to establish a blockade of the ports in question. This procedure is analogous to, but not identical with, the investment by military forces of a fortress in which an army has found shelter in the interior of the enemy's country. But the essential difference is that the land fortress can be completely invested so that no food or other supplies can reach it, whereas a sea fortress cannot, unless it is situated on a small island, be completely invested by naval force alone. In the one case, even if no assault is attempted, starvation must sooner or later bring about the surrender of the fortress together with any military force it contains, whereas in the other the blockaded port being, as a rule, in open communication with its own national territory, cannot be reduced by starvation. Moreover, for reasons already explained, a maritime fortress cannot nowadays be so closely blockaded as to prevent the exit of small craft almost at all times or even to prevent the exit of squadrons of battleships in circumstances favourable to the enterprise. Now the exit of small craft equipped for torpedo attack is a much more serious threat to the blockader than the exit of small craft, not so equipped, was in the old days of close blockade. In those days small craft could do no harm to ships of the line or even to frigates, whereas a torpedo craft is nowadays in certain circumstances the equal and more than the equal of a battleship. For these reasons the escape from a blockaded port of a squadron of battleships might easily be regarded by the blockading enemy as a less serious and even much more welcome incident of the campaign than the frequent issue of swarms of torpedo craft skilfully handled, daringly navigated, and sternly resolved to do or die in the attempt to reduce the battle superiority of the enemy.