What do we mean by “sea-power” and “command of the sea”? What really is a navy and how does it gain these things? How come navies into existence? Of what constituents, human and material, are they composed? How are the human elements taught, trained, commanded, and led? How are the ships grouped and distributed, and the weapons fought in war?

To the countrymen of Nelson, and to those of his great interpreter, Mahan, these might at first sight seem very superfluous questions, for they, almost of natural instinct, should understand that strange but overwhelming force that has made them. To the Kingdom of Great Britain and Ireland, to the Empires that owe allegiance to the British Crown, to the United States of America, sea-power is at once their origin and the fundamental essential of their continued free and independent existence. And it is their predominant races that have produced the world’s greatest sea fighters and sea writers. It is to the British Fleet that the world owes its promise of safety from German diabolism bred of autocracy. It is to sea-power that America must look if she is to finish the work the Allies have begun. With so great a stake in the sea, Great Britain and America should have fathomed its mysteries.

But, despite the fighters and the writers, the sea in a great measure has kept its secret hidden. In every age the truth has been the possession of but a few. Countries34 for a time have followed the light, and have then, as it were, been suddenly struck blind, and the fall of empires has followed the loss of vision. The world explains the British Empire of to-day, and the great American nation which has sprung from it, by a happy congenital talent for colonizing waste places, for self-government, for assimilating and making friends with the unprogressive peoples, by giving them a better government than they had before. And certainly without such gifts the British races could not have overspread so large a portion of the earth. But the world is apt to forget that there were other empires sprung from other European peoples—Portuguese, French, Spanish, and Dutch—each at some time larger in wealth, area, or population, than that which owed allegiance to the British Crown. In each case it was the power of their navies that gave each country these great possessions. Of some of these empires only insignificant traces remain to-day. They have been merged in the British Empire or have become independent. And the merging or the freeing has always followed from war at sea. It is the British sailors, and not the British colonists, that have made the British Empire. It is not because the settlers in New England were better fighters or had more talent for self-government, but because Holland had the weaker navy, that the city which must shortly be the greatest in the world is named after the ancient capital of Northern England, and not after Amsterdam. It was not England’s half-hearted fight on land, but her failure to preserve an unquestionable command of the sea that secured the extraordinary success of Washington and Hamilton’s military plans.

To all these truths we have long paid lip service. Years ago it passed into a commonplace that should ever national35 existence be threatened by an outside force, it would be on the sea that we should have to rely for defence. With so tremendous an issue at stake, why was our knowledge so vague, why has our curiosity to know the truth been so feeble? Perhaps it is that communities that are very rich and very comfortable are slow to believe that danger can hang over them. In the catechism used to teach Catholic children the elements of their religion, the death that awaits every mortal, the instant judgment before the throne of God, the awful alternatives, Heaven or Hell, that depend on the issue, are spoken of as the “Four Last Things.” Their title has been flippantly explained by the admitted fact that they are the very last things that most people ever think of. So has it been with America and England in the matter of war. The threat seemed too far off to be a common and universal concern. It could be left to the governments. So long as we voted all the money that was asked for officially, we had done our share. And, if statesmen told us that our naval force was large enough, and that it was in a state of high efficiency, and ready for war, we felt no obligation to ask what war meant, in what efficiency consisted, or how its existence could be either presumed or proved. We had no incentive to master the thing for ourselves. We were not challenged to inquire whether in fact the semblance of sea-power corresponded with its reality. The fact that it was on sea-power that we relied for defence against invasion should, of course, have quickened our vigilance. It, in fact, deadened it. For we had never refused a pound the Admiralty had asked for. We took the sufficiency of the Navy for granted and, with the buffer of the fleet between ourselves and ruin, the threat of ruin seemed all the more remote.

A minority, no doubt, was uneasy and did inquire. But36 they found their path crossed by difficulties almost insuperable. The literature of sea-power was based entirely upon the history of the great sea wars of a dim past. Mahan, it is true, had so elucidated the broad doctrines of sea strategy that it seemed as if he who ran might read. But lucid and convincing as is his analysis, urbane and judicial as is his style, Mahan’s work could not make the bulk of his readers adepts in naval doctrine. The fact seems to be that the fabled mysteries of the sea make every truth concerning it elusive, difficult for any one but a sailor to grasp. The difficulties were hardly lessened by Mahan’s chief work having dealt completely with the past. The most important of the world’s sea wars may be said to begin with the Armada and to end in 1815. In these two and one quarter centuries the implements of naval warfare changed hardly at all. Broadly speaking, from the days of Howard of Effingham to those of Fulton and Watt, man used three-masted ships and muzzle-loading cannon. Hence the history of the Great Age deals very little with the technique of war.

To the lay reader, therefore, the study of sea-power, based upon these ancient campaigns, seemed not only the pursuit of a subject vague and elusive in itself, but one that becomes doubly unreal through the successive revolutions of modern times. It was like studying the politics of an extinct community told in records of a dead language. The incendiary shell, armour to keep the shell out, steam that made ships completely dirigible in the sense that they could with great rapidity be turned to any chosen course, these alone had, by the middle of the last century, completely revolutionized the tactical employment of sea force. Steam, which made a ship easier to aim than a gun, gave birth to ramming; and naval thought was hypnotized by37 this fallacy for nearly two generations. By the end of the century the whole art had again been changed, first by the development of the monster cannon, and next, a far more important invention, the mountings that made first light, and then heavy, guns so flexible in use that they could be aimed in a moderate sea way. These and the invention of the fish torpedo and the high speed boat for carrying it—that in the twilight of dawn and eve would make it practically invisible—brought about fresh changes that altered not only the tactics of battle, but those of blockade and of many other naval operations.

But, great and surprising as were the changes and developments in naval weapons and the material in the last half of the nineteenth century, they were completely eclipsed by the number and nature of the advances made in the first decade and a half of the twentieth. If, to the ordinary reader, the lessons of the past seemed of doubtful value in the light of what steam, the explosive shell, the torpedo, and the heavy gun had effected, what was to be said in the light of the kaleidoscope of novelties sprung upon the world after the latest of all the naval wars? For between 1906 and 1914 there came a succession of naval sensations so startling as to make clear and connected thinking appear a visionary hope.

First we heard that naval guns, that until 1904 had nowhere been fired at a greater range than two miles, were actually being used in practice—and used with success—at distances of ten, twelve, and fourteen thousand yards. It was not only that guns were increasing their range, they were growing monstrously in size and still more monstrously in the numbers put into each individual ship, so that the ships grew faster than the guns themselves, until the capital ship of to-day is more than double the displacement38 of that of ten years ago. And with size came speed, not only the speed that would follow naturally from the increase in length, but the further speed that was got by a more compact and lighter form of prime mover. Ten years ago the highest action pace a fleet of capital ships would have been, perhaps, seventeen knots. Now whole squadrons can do twenty-five per cent. better. And with the battle-cruiser we have now a capital ship carrying the biggest guns there are, that can take them into action literally twice as fast as a twelve-inch gun could be carried into battle twelve years ago. Thus with range increased out of all imagination, and vastly greater speed, the tactics of battle were obviously in the melting pot.

But these were far from being the only revolutionary elements. There followed in quick succession a new torpedo that ran with almost perfect accuracy for five or six miles and carried an explosive charge three or four times larger than anything previously known. It had seemed but yesterday that a mile was the torpedo’s almost outside range. Then, at the beginning of the decade of which I speak, the submarine had a low speed on the surface, and half of that below it, with a very limited area of man?uvre in which it could work. It seemed little more, many thought, than an ingenious toy capable, perhaps, of an occasional deadly surprise if an enemy’s fleet should come too near a harbour, but seemingly not destined to influence the grand tactics of war. But in an incredibly short time the submarine became a submersible ocean cruiser, with three times the radius of a pre-Dreadnought battleship, with a far higher surface speed, and able to carry guns of such power that they could sink a merchant ship with half-a-dozen rounds at four miles. In this, even the dullest could see something more than a change in naval tactics.39 Might not the whole nature of naval war be changed? For the long range torpedo that could be used in action, at a range equal to that at which the greatest guns could be expected to hit; the submarine that, completely hidden, could bring the torpedo to such short range that hits would be a certainty, the invisible boat that could evade the closest surface cordon and, almost undisturbed, hunt and destroy merchantmen on the trade routes—that, but for the submarine, would have been completely protected by the command won by the predominant fleet—wonderful as these new things were, they were far from exhausting the new developments of under-water war. Great ingenuity had been shown not only in developing very powerful mines, but in devising means of laying them by the fastest ships, so that not only could these deadly traps be set by merchantmen disguised as neutrals, but by fast cruisers whose speed could at any time enable them to evade the patrols. And, finally, it was equally obvious that the submarine could become a mine layer also. There was, then, literally no spot in the ocean that might not at any moment be mined.

Add to all this, that while wireless introduced an almost instant means of sending orders to or getting news from such distant spots that space was annihilated, airships and aeroplanes—with some, as many thought, with a decisive capacity for attacking fleets in harbour—seemed to make scouting possible over unthought of areas. Can we blame the landsman who set himself patiently to learn the rudiments of the naval art if, after a painful study of the past, he found himself so bemused by the changes of the present as to wonder if a single accepted dogma could survive the high-explosive bombardment of to-day’s inventions? It almost looked as if nothing could be learned40 from the past and less, if possible, be foretold about the future. If the understanding of sea-power in the days of old had been the possession of but a few, it seemed that to-day it must be denied to all.

It is, therefore, not surprising that extraordinary misunderstandings were—and are—prevalent. Only one truth seemed to survive—the supremacy of the capital ship. But this, too, became an error, because it excluded other truths. To the vast bulk of laymen the word “navy” suggested no more than a panorama of great super-Dreadnought battleships. From time to time naval reviews had been held, and the illustrated papers had shown these great vessels, long vistas of them, anchored in perfectly kept lines, with light cruisers and destroyers fading away into the distance. Both in the pictures and in the descriptions all emphasis was laid upon the ships. And in this the current official naval thought of the day was reflected. If any one wished to compare the British Fleet with the German or the German with the American, he confined himself to enumerating their respective totals in Dreadnoughts, and let it go at that. His mental picture of a fleet was thus a perspective of vast mastodons armed with guns of fabulous reach and still more fabulous power, gifted, some of them, with speed that could outstrip the fastest liner, and encased, at least in part, in almost impenetrable armour.

He would know generally, of course, that such things as cruisers, destroyers, and submarines not only existed, but were indeed necessary. He would know vaguely that cruisers were useful for cruising, and destroyers for their eponymous duties—though he would have been sorely puzzled if he had been asked to say exactly what the cruising was for, or what the destroyers were intended to destroy.41 He would have heard of the mystic properties of torpedoes, and of mines, and of certain weird possibilities that lay before the combination of the torpedo with the submarine. Similarly, if one challenged him, he would admit, of course, that guns could only be formidable if they hit, and that fleets could only succeed in battle if their officers and crews were properly trained and skilfully led. But these were things that could not be tabulated or scheduled. They did not figure in Naval Annuals, nor in Admiralty statements. They were stumbling blocks to the layman’s desire to be satisfied—and he took it for granted that they were all right, and was content to measure naval strength by the number of the biggest ships, and so rate the navies of the world by what they possessed in these colossal units only. Thus, he would always put Great Britain first, and recently Germany second, with the United States, Japan, and France taking the third place in succession, as their annual programmes of construction were announced. And just as he thought of navies in terms of battleships, so he thought of naval war in terms of great sea battles. A reaction was inevitable.

Four years have now passed since Germany struck her felon blow at the Christian tradition the nations have been struggling to maintain—and so far there has been no Trafalgar. The German Fleet, hidden behind its defences, is still integral and afloat, and though the British Fleet has again and again come out, its battleships have got into action but once, and then for a few minutes only. For four years, therefore, the two greatest battle fleets in the world seem to have been doing nothing; and to be doing nothing now! And so, if you ask the average layman for a broad opinion on sea-power to-day, he will tell you that battle fleets are useless. For a year or more he has heard42 little of any work at sea except of the work of the submarine. To him, therefore, it seemed manifest that the torpedo has superseded the gun and the submarine the battleship. His opinions, in other words, have swung full cycle. Was he right before and is he wrong now, or was his first view an error and has he at last, under the stern teachings of war, attained the truth?

He was wrong then and he is wrong now. It was an error to think of sea-power only in terms of battleships. It is a still greater error to suppose that sea-power can exist in any useful form unless based on battleships in overwhelming strength. It is true that the German submarines did for a period so threaten the world’s shipping as to make it possible that the overwhelming military resources of the Allies might never be brought to bear against the full strength of the German line in France. It is also true that they have added years to the duration of the war, millions and millions to its cost, and have brought us to straits that are hard to bear. They were truly Germany’s most powerful defence, the only useful form of sea force for her. But it is, nevertheless, quite impossible that the submarine can give to Germany any of the direct advantages which the command of the sea confers.

These simple truths will come home convincingly to us if we suppose for a minute that, at the only encounter in which the battle fleets met, it had been the German Fleet that was victorious. Had Scheer and Von Hipper met Beatty and Jellicoe in a fair, well-fought-out action, and sunk or captured the greater part of the British Fleet so that but a crippled remnant could struggle back to harbour—as little left of the mighty British armada as survived of Villeneuve’s and Gravina’s forces after Trafalgar—would it ever have been necessary for Germany to have challenged43 the forbearance of the world by reckless and piratical attacks on peaceful shipping? Quite obviously not. For with her battle-cruisers patrolling unchallenged in the Channel, the North Sea, and the Atlantic, with all her destroyers and light cruisers working under their protection, no British merchantman could have cleared or entered any British port, no neutral could have passed the blockading lines. British submarines might, indeed, have held up German shipping—but we should have lost the use of merchant shipping ourselves. Our armies would have been cut off from their overseas base, our fighting Allies would have been robbed of the food and material now reaching them from North and South America and the British Dominions, and the civil population of England, Scotland, Ireland, and Wales, would have been threatened by immediate invasion or by not very far distant famine. And this is so because command of the sea is conditioned by a superior battleship strength, and can only be exercised by surface craft which cannot be driven off the sea.

Let us look at this question again from another angle. It is probable that Germany possessed, during the summer of 1917, some two hundred submarines at least. She may have possessed more. These submarines were, for many months, sinking on an average of from twenty to twenty-four British ships a week, and perhaps rather more than half as many Allied and neutral ships as well. It was, of course, a very formidable loss. But of every seventeen ships that went into the danger zone, sixteen did actually escape. How many would have escaped if Germany could have maintained a fleet of fifty surface ships—light cruisers, armed merchantmen, swift destroyers—in these waters? Supposing trade ships were to put to sea and try44 to get past such a cordon just as they risk passing the submarines, how many could possibly escape? What would be the toll each surface ship would take—one a fortnight? One a week? One a day?

These are all ridiculous questions, because, could such a cordon be maintained, no ship bound for Great Britain would put to sea at all. It would not be sixteen escaping to one captured; the whole seventeen would so certainly be doomed that they all would stay in port. So much the war has certainly taught us. When, on August 4, 1914, the British Government declared war on Germany, the sailing of every German ship the world over was then and there stopped. A hundred that were at sea could not be warned and were captured. Those that escaped capture made German or neutral ports. But the order not to sail did not wait upon results. The stoppage of the German merchant service was automatic and instantaneous. It would have been raving insanity to have risked encounter with a navy that held the surface command.

Three months later the situation was locally reversed in South American waters. Von Spee, with two very powerful armoured cruisers and three light fast vessels, encountered a very inferior British force under Admiral Cradock off Coronel, and defeated it decisively. Von Spee’s victory meant that in the Southern Atlantic there was no force capable of opposing him. Instantly every South American port was closed. No one knew where Von Spee might turn up next. Not a captain dared clear for England. Even in South Africa General Botha’s hands were tied. A section of the Transvaal and Orange Colony Dutch had risen in rebellion, and had made common cause with the Germans in South West Africa. With Von Spee at large there was no saying what help he would bring to45 the enemy, and the risk that communications with the mother country might be cut, was a real one. For four weeks the South African Government was paralyzed.

Then followed the most brilliant piece of sea strategy in the war. Two battle-cruisers were sent secretly and at top speed to the Falkland Islands. They reached Port Stanley on December 7, and on the next morning at eight o’clock, Von Spee, in obedience to some inexplicable instinct, brought the whole of his forces to attack the islands. It was the most extraordinary coincidence in the history of war. It was as if a man had been told that a sixty-pound salmon had been seen in a certain river, had thrown a fly at random, and had got a bite and landed him with his first cast. The verdict of Coronel was reversed. Four out of five German ships were sunk. The Dresden escaped, but only to hide herself in the fjords of Patagonia. Germany’s brief spell of sea command in the South Atlantic had ended as dramatically as it began. And within twenty-four hours the laden ships of Chile and the Argentine had put to sea, the underwriters had dropped their premiums to the pre-war rate, and the arrangements for the invasion of South West Africa had begun.

Once more it had been proved that the course of sea traffic is governed by sea command, and sea command means the general power to use the ocean for what it truly is, the highway that connects all the ports of the world together. To use, that is to say, exclusively; to limit its use to the power possessing that command, and to those other powers that might be friendly to them, or to neutrals unconcerned with the war altogether. Never in history has this command been complete. From Trafalgar to 1815, the British, if ever, commanded the sea adversely against their enemies. But they lost anything from six hundred46 to one thousand ships a year, and it was never possible to stop the whole of the enemy’s trade. Before submarines were ever heard of, then, command could not be made absolute. Strangely enough, steam changed all this. To-day the surface command against surface force is virtually absolute. In August, 1914, Germany had in all a dozen armed vessels on the high seas prepared to attack British shipping. They took and destroyed fifty-six vessels only. All but three were destroyed or driven to intern in very few months. Save for a raider or two—exceptions that prove the rule—no surface attack has been made on the Allies’ ocean trade since then. And there has been no ocean trade in German bottoms at all. In a sense, then, the submarine has only restored to the weaker belligerent a part—and only a small part—of the powers he possessed in the days of sailing fleets. It gives him a limited power of attack on his enemy’s supply. But, two cruises of the Deutschland notwithstanding, it has returned him none of his old trading power. And, as the course of the submarine war has shown, so long as he limits the attack on trade to proportions which the neutral world can put up with, the power of attack is so restricted as to be without military value. The attempt, then, to get a kind of command of the sea by submarine alone could only be made at the cost of turning the whole neutral world into an enemy world. And from the German point of view, the tragedy of the thing is this. The attempt was made, the whole world has become hostile, and the thing has failed.

In these two popular fallacies—the pre-war error that battleships were everything, and the present error that they are absolutely useless, and that it is the submarine that reigns at sea—we see, as it appears to me, convincing proofs that an exposition of the A B C of sea fighting would47 not be a work of supererogation. I have spoken of these fallacies as popular fallacies, but they are not limited to the unlettered, nor are they foreign to men of affairs. They have, on the contrary, flourished most in ministries, and been strongly held by those whose business it should have been not only to follow or express, but to mould, public opinion. A British statesman, afterwards Prime Minister, said once in Parliament: “I believe that since the Declaration of Paris, the fleet, valuable as it is for preventing an invasion of these shores, is almost valueless for any other purpose.” Most strange of all, the strongest exponents of these heresies have been certain naval officers themselves. It would be interesting to essay to account for this, as it seems to me the strangest curiosity of our times. Let it suffice for the moment to state that what up to a year ago was a dominating faith, is recognized universally to-day as a devastating tissue of errors.

Had the root principles of sea-power been properly understood, these errors never could have prevailed. For it is popular opinion that is ultimately responsible for the kind of government each nation has. On it depends the kind of navy that each government creates, and hence the measure of safety at sea that each nation enjoys. The tragic history of the last four years shows how this opinion can be misguided into an almost fatal tolerance of what is false.

When will a new Mahan arise to set things right? The world needs a naval teacher.