If the doctrine of cruiser control be correct, then every cruiser attached to the battle-fleet is one withdrawn from its true function. Such withdrawals are inevitable. A squadron of battleships is an imperfect organism unable to do its work without cruiser assistance, and since the performance of its work is essential to cruiser freedom, some cruisers must be sacrificed. But in what proportion? If we confine ourselves to the view that command depends on the battle-fleet, then we shall attach to it such a number as its commander may deem necessary to make contact with the enemy absolutely certain and to surround himself with an impenetrable screen. If we knew the enemy was as anxious for a decision as ourselves, such a course might be justified. But the normal condition is that if we desire a decision it is because we have definite hopes of success, and consequently the enemy will probably seek to avoid one on our terms. In practice this means that if we have perfected our arrangements for the destruction of his main fleet he will refuse to expose it till he sees a more favourable opportunity. And what will be the result? He remains on the defensive, and theoretically all the ensuing period of inaction tends to fall into his scale. Without stirring from port his fleet is doing its work. The more closely he induces us to concentrate our cruiser force in face of his battle-fleet, the more he frees the sea for the circulation of his own trade, and the more he exposes ours to cruiser raids.
Experience, then, and theory alike dictate that as a general principle cruisers should be regarded as primarily concerned with the active occupation of communications, and that withdrawals for fleet purposes should be reduced to the furthest margin of reasonable risk. What that margin should be can only be decided on the circumstances of each case as it arises, and by the personal characteristics of the officers who are responsible. Nelson's practice was to reduce fleet cruisers lower than perhaps any other commander. So small indeed was the margin of efficiency he left, that in the campaign already cited, when his judgment was ripest, one stroke of ill-luck—a chance betrayal of his position by a neutral—availed to deprive him of the decision he sought, and to let the enemy's fleet escape.
We arrive, then, at this general conclusion. The object of naval warfare is to control maritime communications. In order to exercise that control effectively we must have a numerous class of vessels specially adapted for pursuit. But their power of exercising control is in proportion to our degree of command, that is, to our power of preventing their operations being interfered with by the enemy. Their own power of resistance is in inverse proportion to their power of exercising control; that is to say, the more numerous and better adapted they are for preying on commerce and transports, the weaker will be their individual fighting power. We cannot give them as a whole the power of resisting disturbance without at the same time reducing their power of exercising control. The accepted solution of the difficulty during the great period of Anson's school was to provide them with a covering force of battle units specially adapted for fighting. But here arises a correlative difficulty. In so far as we give our battle units fighting power we deny them scouting power, and scouting is essential to their effective operation. The battle-fleet must have eyes. Now, vessels adapted for control of communications are also well adapted for "eyes." It becomes the practice, therefore, to withdraw from control operations a sufficient number of units to enable the battle-fleet to cover effectively the operations of those that remain.
Such were the broad principles on which the inevitable dilemma always had to be solved, and on which Anson's organisation was based. They flow naturally from the communication theory of maritime war, and it was this theory which then dominated naval thought, as is apparent from the technical use of such phrases as "lines of passage and communication." The war plans of the great strategists from Anson and Barham can always be resolved into these simple elements, and where we find the Admiralty grip of them loosened, we have the confusion and quite unnecessary failures of the War of American Independence. In that mismanaged contest the cardinal mistake was that we suffered the enemy's battle-fleets to get upon and occupy the vital lines of "passage and communication" without first bringing them to action, an error partly due to the unreadiness of a weak administration, and partly to an insufficient allocation of cruisers to secure contact at the right places.
So far, then, the principles on which our naval supremacy was built up are clear. For the enemies with whom we had to deal Anson's system was admirably conceived. Both Spain and France held the communication theory so strongly, that they were content to count as success the power of continually disturbing our control without any real attempt to secure it for themselves. To defeat such a policy Anson's constitution and the strategy it connoted were thoroughly well adapted and easy to work. But it by no means follows that his doctrine is the last word. Even in his own time complications had begun to develop which tended to confuse the precision of his system. By the culminating year of Trafalgar there were indications that it was getting worn out, while the new methods and material used by the Americans in 1812 made a serious rent in it. The disturbances then inaugurated have continued to develop, and it is necessary to consider how seriously they have confused the problem of fleet constitution.
Firstly, there is the general recognition, always patent to ourselves, that by far the most drastic, economical, and effective way of securing control is to destroy the enemy's means of interfering with it. In our own service this "overthrow" idea always tended to assert itself so strongly, that occasionally the means became for a time more important than the end; that is to say, circumstances were such that on occasions it was considered advisable to sacrifice the exercise of control for a time in order quickly and permanently to deprive the enemy of all means of interference. When there was reasonable hope of the enemy risking a decision this consideration tended to override all others; but when, as in Nelson's case in the Mediterranean, the hope was small, the exercise of control tended to take the paramount place.
The second complexity arose from the fact that however strong might be our battleship cover, it is impossible for it absolutely to secure cruiser control from disturbance by sporadic attack. Isolated heavy ships, taking advantage of the chances of the sea, could elude even the strictest blockade, and one such ship, if she succeeded in getting upon a line of communication, might paralyse the operations of a number of weaker units. They must either run or concentrate, and in either case the control was broken. If it were a squadron of heavy ships that caused the disturbance, the practice was to detach against it a division of the covering battle-fleet. But it was obviously highly inconvenient and contrary to the whole idea on which the constitution of the fleet was based to allow every slight danger to cruiser control to loosen the cohesion of the main fleet.
It was necessary, then, to give cruiser lines some power of resistance. This necessity once admitted, there seemed no point at which you could stop increasing the fighting power of your cruisers, and sooner or later, unless some means of checking the process were found, the distinction between cruisers and battleships would practically disappear. Such a means was found in what may be called the "Intermediate" ship. Frigates did indeed continue to increase in size and fighting power throughout the remainder of the sailing era, but it was not only in this manner that the power of resistance was gained. The evil results of the movement were checked by the introduction of a supporting ship, midway between frigates and true ships-of-the-line. Sometimes classed as a battleship, and taking her place in the line, the 50-gun ship came to be essentially a type for stiffening cruiser squadrons. They most commonly appear as the flagships of cruiser commodores, or stationed in terminal waters or at focal points where sporadic raids were likely to fall and be most destructive. The strategical effect of the presence of such a vessel in a cruiser line was to give the whole line in some degree the strength of the intermediate ship; for any hostile cruiser endeavouring to disturb the line was liable to have to deal with the supporting ship, while if a frigate and a 50-gun ship got together they were a match even for a small ship-of-the-line.
In sailing days, of course, this power of the supporting ship was weak owing to the imperfection of the means of distant communication between ships at sea and the non-existence of such means beyond extreme range of vision. But as wireless telegraphy develops it is not unreasonable to expect that the strategic value of the supporting or intermediate ship will be found greater than it ever was in sailing days, and that for dealing with sporadic disturbance the tendency will be for a cruiser line to approximate more and more in power of resistance to that of its strongest unit.
For fleet service a cruiser's power of resistance was hardly less valuable; for though we speak of fleet cruisers as the eyes of the fleet, their purpose is almost equally to blindfold the enemy. Their duty is not only to disclose the movements of the enemy, but also to act as a screen to conceal our own. The point was specially well marked in the blockades, where the old 50-gun ships are almost always found with the inshore cruiser squadron, preventing that squadron being forced by inquisitive frigates. Important as this power of resistance in the screen was in the old days, it is tenfold more important now, and the consequent difficulty of keeping cruisers distinct from battleships is greater than ever. The reason for this is best considered under the third and most serious cause of complexity.
The third cause is the acquisition by the flotilla of battle power. It is a feature of naval warfare that is entirely new.10 For all practical purposes it was unknown until the full development of the mobile torpedo. It is true that the fireship as originally conceived was regarded as having something of the same power. During the Dutch wars—the heyday of its vogue—its assigned power was on some occasions actually realised, as in the burning of Lord Sandwich's flagship at the battle of Solebay, and the destruction of the Spanish-Dutch fleet at Palermo by Duquesne. But as the "nimbleness" of great-ships increased with the ripening of seamanship and naval architecture, the fireship as a battle weapon became almost negligible, while a fleet at anchor was found to be thoroughly defensible by its own picket-boats. Towards the middle of the eighteenth century indeed the occasions on which the fireship could be used for its special purpose was regarded as highly exceptional, and though the type was retained till the end of the century, its normal functions differed not at all from those of the rest of the flotilla of which it then formed part.
Those functions, as we have seen, expressed the cruising idea in its purest sense. It was numbers and mobility that determined flotilla types rather than armament or capacity for sea-endurance. Their primary purpose was to control communications in home and colonial waters against weakly armed privateers. The type which these duties determined fitted them adequately for the secondary purpose of inshore and despatch work with a fleet. It was, moreover, on the ubiquity which their numbers gave them, and on their power of dealing with unarmed or lightly armed vessels, that we relied for our first line of defence against invasion. These latter duties were of course exceptional, and the Navy List did not carry as a rule sufficient numbers for the purpose. But a special value of the class was that it was capable of rapid and almost indefinite expansion from the mercantile marine. Anything that could carry a gun had its use, and during the period of the Napoleonic threat the defence flotilla rose all told to considerably over a thousand units.
Formidable and effective as was a flotilla of this type for the ends it was designed to serve, it obviously in no way affected the security of a battle-fleet. But so soon as the flotilla acquired battle power the whole situation was changed, and the old principles of cruiser design and distribution were torn to shreds. The battle-fleet became a more imperfect organism than ever. Formerly it was only its offensive power that required supplementing. The new condition meant that unaided it could no longer ensure its own defence. It now required screening, not only from observation, but also from flotilla attack. The theoretical weakness of an arrested offensive received a practical and concrete illustration to a degree that war had scarcely ever known. Our most dearly cherished strategical traditions were shaken to the bottom. The "proper place" for our battle-fleet had always been "on the enemy's coasts," and now that was precisely where the enemy would be best pleased to see it. What was to be done? So splendid a tradition could not lightly be laid aside, but the attempt to preserve it involved us still deeper in heresy. The vital, most difficult, and most absorbing problem has become not how to increase the power of a battle-fleet for attack, which is a comparatively simple matter, but how to defend it. As the offensive power of the flotilla developed, the problem pressed with an almost bewildering intensity. With every increase in the speed and sea-keeping power of torpedo craft, the problem of the screen grew more exacting. To keep the hostile flotilla out of night range the screen must be flung out wider and wider, and this meant more and more cruisers withdrawn from their primary function. And not only this. The screen must not only be far flung, but it must be made as far as possible impenetrable. In other words, its own power of resistance must be increased all along the line. Whole squadrons of armoured cruisers had to be attached to battle-fleets to support the weaker members of the screen. The crying need for this type of ship set up a rapid movement for increasing their fighting power, and with it fell with equal rapidity the economic possibility of giving the cruiser class its essential attribute of numbers.
As an inevitable result we find ourselves involved in an effort to restore to the flotilla some of its old cruiser capacity, by endowing it with gun armament, higher sea-keeping power, and facilities for distant communication, all at the cost of specialisation and of greater economic strain. Still judged by past experience, some means of increasing numbers in the cruising types is essential, nor is it clear how it is possible to secure that essential in the ranks of the true cruiser. No point has been found at which it was possible to stop the tendency of this class of vessel to increase in size and cost, or to recall it to the strategical position it used to occupy. So insecure is the battle-squadron, so imperfect as a self-contained weapon has it become, that its need has overridden the old order of things, and the primary function of the cruising ship inclines to be no longer the exercise of control under cover of the battle-fleet. The battle-fleet now demands protection by the cruising ship, and what the battle-fleet needs is held to be the first necessity.
Judged by the old naval practice, it is an anomalous position to have reached. But the whole naval art has suffered a revolution beyond all previous experience, and it is possible the old practice is no longer a safe guide. Driven by the same necessities, every naval Power is following the same course. It may be right, it may be wrong; no one at least but the ignorant or hasty will venture to pass categorical judgment. The best we can do is to endeavour to realise the situation to which, in spite of all misgivings, we have been forced, and to determine its relations to the developments of the past.
It is undoubtedly a difficult task. As we have seen, there have prevailed in the constitution of fleets at various times several methods of expressing the necessities of naval war. The present system differs from them all. On the one hand, we have the fact that the latest developments of cruiser power have finally obliterated all logical distinction between cruisers and battleships, and we thus find ourselves hand in hand with the fleet constitution of the old Dutch wars. On the other, however, we have armoured cruisers organised in squadrons and attached to battle-fleets not only for strategical purposes, but also with as yet undeveloped tactical functions in battle. Here we come close to the latest development of the sailing era, when "Advanced" or "Light" squadrons began to appear in the organisation of battle-fleets.
The system arose towards the end of the eighteenth century in the Mediterranean, where the conditions of control called for so wide a dispersal of cruisers and so great a number of them, that it was almost imperative for a battle-squadron in that sea to do much of its own scouting. It was certainly for this purpose that the fastest and lightest ships-of-the-line were formed into a separate unit, and the first designation it received was that of "Observation Squadron." It remained for Nelson to endeavour to endow it with a tactical function, but his idea was never realised either by himself or any of his successors.
Side by side with this new element in the organisation of a battle-fleet, which perhaps is best designated as a "Light Division," we have another significant fact. Not only was it not always composed entirely of ships-of-the-line, especially in the French service, but in 1805, the year of the full development, we have Sir Richard Strachan using the heavy frigates attached to his battle-squadron as a "Light Division," and giving them a definite tactical function. The collapse of the French Navy put a stop to further developments of either idea. Whither they would have led we cannot tell. But it is impossible to shut our eyes to the indication of a growing tendency towards the system that exists at present. It is difficult at least to ignore the fact that both Nelson and Strachan in that culminating year found the actuality of war calling for something for which there was then no provision in the constitution of the fleet, but which it does contain to-day. What Nelson felt for was a battleship of cruiser speed. What Strachan desired was a cruiser fit to take a tactical part in a fleet action. We have them both, but with what result? Anson's specialisation of types has almost disappeared, and our present fleet constitution is scarcely to be distinguished from that of the seventeenth century. We retain the three-fold nomenclature, but the system itself has really gone. Battleships grade into armoured cruisers, armoured cruisers into protected cruisers. We can scarcely detect any real distinction except a twofold one between vessels whose primary armament is the gun and vessels whose primary armament is the torpedo. But even here the existence of a type of cruiser designed to act with flotillas blurs the outline, while, as we have seen, the larger units of the flotilla are grading up to cruiser level.
We are thus face to face with a situation which has its closest counterpart in the structureless fleets of the seventeenth century. That naval thought should have so nearly retraced its steps in the course of two centuries is curious enough, but it is still more striking when we consider how widely the underlying causes differ in each case. The pressure which has forced the present situation is due most obviously to two causes. One is the excessive development of the "intermediate" ship originally devised for purposes of commerce protection, and dictated by a menace which the experience of the American War had taught us to respect. The other is the introduction of the torpedo, and the consequent vulnerability of battle-squadrons that are not securely screened. Nothing of the kind had any influence on the fleet constitution of the seventeenth century. But if we seek deeper, there is a less obvious consideration which for what it is worth is too striking to be ignored.
It has been suggested above that the constitution of fleets appears to have some more or less recognisable relation to the prevalent theory of war. Now, amongst all our uncertainty we can assert with confidence that the theory which holds the field at the present day bears the closest possible resemblance to that which dominated the soldier-admirals of the Dutch war. It was the "Overthrow" theory, the firm faith in the decisive action as the key of all strategical problems. They carried it to sea with them from the battlefields of the New Model Army, and the Dutch met them squarely. In the first war at least their commerce had to give place to the exigencies of throwing into the battle everything that could affect the issue. It is not of course pretended that this attitude was dictated by any clearly conceived theory of absolute war. It was due rather to the fact that, owing to the relative geographical conditions, all attempts to guard trade communications were useless without the command of the home waters in the North Sea, and the truth received a clinching moral emphasis from the British claim to the actual dominion of the Narrow Seas. It was, in fact, a war which resembled rather the continental conditions of territorial conquest than the naval procedure that characterised our rivalry with France.
Is it then possible, however much we may resist the conclusion in loyalty to the eighteenth-century tradition, that the rise of a new naval Power in the room of Holland must bring us back to the drastic, if crude, methods of the Dutch wars, and force us to tread under foot the nicer ingenuity of Anson's system? Is it this which has tempted us to mistrust any type of vessel which cannot be flung into the battle? The recurrence of a formidable rival in the North Sea was certainly not the first cause of the reaction. It began before that menace arose. Still it has undoubtedly forced the pace, and even if it be not a cause, it may well be a justification.