As to which of the two plans he would adopt, the inference is that his choice would depend on the strength of the enemy, for it was reported the Rochefort squadron had joined Roquefeuille. The doubt was quickly settled. On the morrow he heard that Roquefeuille was at Dungeness with only fifteen of the line. In a moment he seized all the advantage of the interior position which Roquefeuille's necessity to close on the army had given him. With admirable insight he saw there was time to fling his whole force at the enemy's fleet without losing his hold on the army's line of passage. The movement was made immediately. The moment the French were sighted "General chase" was signalled, and Roquefeuille was within an ace of being surprised at his anchorage when a calm stopped the attack. The calm was succeeded by another furious gale, in which the French escaped in a disastrous sauve qui peut, and the fleet of transports was destroyed. The outcome of it all was not only the failure of the invasion, but that we secured the command of home waters for the rest of the war.
The whole attempt, it will be seen, with everything in its favour, had exhibited the normal course of degradation. For all the nicely framed plan and the perfect deception, the inherent difficulties, when it came to the point of execution, had as usual forced a clumsy concentration of the enemy's battle-fleet with his transports, and we on our part were able to forestall it with every advantage in our favour by the simple expedient of a central mass on a revealed and certain line of passage.
In the next project, that of 1759, a new and very clever plan was devised for turning the difficulty. The first idea of Marshal Belleisle, like that of Napoleon, was to gather the army at Ambleteuse and Boulogne, and to avoid the assemblage of transports by passing it across the Strait by stealth in flat boats. But this idea was abandoned before it had gone very far for something much more subtle. The fallacious advantage of a short passage was dropped, and the army was to start from three widely separated points all in more open waters—a diversionary raid from Dunkirk and two more formidable forces from Havre and the Morbihan in South Brittany. To secure sufficient control there was to be a concentration on the Brest fleet from the Mediterranean and the West Indies.
The new feature, it will be observed, was that our covering fleet—that is, the Western Squadron off Brest—would have two cruiser blockades to secure, one on either side of it. Difficult as the situation looked, it was solved on the old lines. The two divisions of the French army at Dunkirk and Morbihan were held by cruiser squadrons capable of following them over the open sea if by chance they escaped, while the third division at Havre, which had nothing but flat boats for transport, was held by a flotilla well supported. Its case was hopeless. It could not move without a squadron to release it, and no fortune of weather could possibly bring a squadron from Brest. Hawke, who had the main blockade, might be blown off, but he could scarcely fail to bring to action any squadron that attempted to enter the Channel. With the Morbihan force it was different. Any time that Hawke was blown off a squadron could reach it from Brest and break the cruiser blockade. The French Government actually ordered a portion of the fleet to make the attempt. Conflans however, who was in command, protested his force was too weak to divide, owing to the failure of the intended concentration. Boscawen had caught and beaten the Mediterranean squadron off Lagos, and though the West Indian squadron got in, it proved, as in Napoleon's great plan of concentration, unfit for further service. The old situation had arisen, forced by the old method of defence; and in the end there was nothing for it but for Conflans to take his whole fleet to the Morbihan transports. Hawke was upon him at once, and the disastrous day of Quiberon was the result. The Dunkirk division alone got free, but the smallness of its size, which permitted it to evade the watch, also prevented its doing any harm. Its escort, after landing its handful of troops in Ireland, was entirely destroyed; and so again the attempt of the French to invade over an uncommanded sea produced no effect but the loss of their fleet.
The project of 1779 marked these principles even more strongly, for it demonstrated them working even when our home fleet was greatly inferior to that of the enemy. In this case the invader's idea was to form two expeditionary forces at Cherbourg and Havre, and under cover of an overwhelming combination of the Spanish and French fleets, to unite them at sea and seize Portsmouth and the Isle of Wight. It was in the early summer we got wind of the scheme, and two cruiser squadrons and flotillas were at once formed at the Downs and Channel Islands to watch the French coasts and prevent the concentration of transports. Spain had not yet declared war, but she was suspected, and the main fleet, under the veteran Sir Charles Hardy, who had been Norris's second in command in 1744, was ordered to proceed off Brest and prevent any Spanish squadron that might appear from entering that port. The French, however, outmanoeuvred us by putting to sea before Hardy could reach his station and forming a junction with the Spaniards off Finisterre. The combined fleet contained about fifty of the line, nearly double our own. The army of invasion, with Dumouriez for its Chief of the Staff, numbered some 50,000 men, a force we were in no condition to meet ashore. Everything, therefore, was in favour of success, and yet in the navy, at least, a feeling of confidence prevailed that no invasion could take place.
The brains of the naval defence were Lord Barham (then Sir Charles Middleton) at the Admiralty and Kempenfelt as Chief of the Staff in the fleet; and it is to their correspondence at this time that we owe some of the most valuable strategical appreciations we possess. The idea of the French was to come into the Channel in their overwhelming force, and while they destroyed or held Hardy, to detach a sufficient squadron to break the cruiser blockade and escort the troops across. Kempenfelt was confident that it could not be done. He was sure that the unwieldy combined mass could be rendered powerless by his comparatively homogeneous and mobile fleet, inferior as it was, so long as he could keep it at sea and to the westward. The appreciation of the power of a nimble inferior fleet which he wrote at this time has already been given.23 When the worst of the position was fully known, and the enemy was reported off the mouth of the Channel, he wrote another to Middleton. His only doubt was whether his fleet had the necessary cohesion and mobility. "We don't seem," he said, "to have considered sufficiently a certain fact that the comparative force of two fleets depends much upon their sailing. The fleet that sails fastest has much the advantage, as they can engage or not as they please, and so have always in their power to choose the favourable opportunity to attack. I think I may safely hazard an opinion that twenty-five sail of the line coppered would be sufficient to harass and tease this great unwieldy combined Armada so as to prevent their effecting anything, hanging continually upon them, ready to catch at any opportunity of a separation from night, gale or fog, to dart upon the separated, to cut off convoys of provisions coming to them, and if they attempted an invasion, to oblige their whole fleet to escort the transports, and even then it would be impossible to protect them entirely from so active and nimble a fleet."
Here we have from the pen of one of the greatest masters the real key of the solution—the power, that is, of forcing the mass of the enemy's fleet to escort the transports. Hardy, of course, knew it well from his experience of 1744, and acted accordingly. This case is the more striking, since defence against the threatened invasion was not the whole of the problem he had to solve. It was complicated by instructions that he must also prevent a possible descent on Ireland, and cover the arrival of the great convoys. In reply, on August 1st, he announced his intention of taking station ten to twenty leagues W.S.W. of Scilly, "which I am of opinion," he said, "is the most proper station for the security of the trade expected from the East and West Indies, and for the meeting of the fleets of the enemy should they attempt to come into the Channel." He underlined the last words, indicating, apparently, his belief that they would not venture to do so so long as he could keep his fleet to the westward and undefeated. This at least he did, till a month later he found it necessary to come in for supplies. Then, still avoiding the enemy, he ran not to Plymouth, but right up to St. Helen's. The movement is always regarded as an unworthy retreat, and it caused much dissatisfaction in the fleet at the time. But it is to be observed that his conduct was strictly in accordance with the principle which makes the invading army the primary objective. If Hardy's fleet was no longer fit to keep the sea without replenishment, then the proper place to seek replenishment was on the invader's line of passage. So long as he was there, invasion could not take place till he was defeated. The allies, it was true, were now free to join their transports, but the prospect of such a movement gave the admiral no uneasiness, for it would bring him the chance of serving his enemy as the Spaniards were served in 1588. "I shall do my utmost," he said, "to drive them up the Channel." It is the old principle. If the worst comes to the worst, so long as you are able to force the covering fleet upon the transports, and especially in narrow waters, invasion becomes an operation beyond the endurable risks of war.
So it proved. On August 14th Count d'Orvilliers, the allied commander-in-chief, had made the Lizard, and for a fortnight had striven to bring Hardy to decisive action. Until he had done so he dared neither enter the Channel with his fleet nor detach a squadron to break the cruiser blockades at the invasion bases. His ineffectual efforts exhausted his fleet's endurance, which the distant concentration at Finisterre had already severely sapped, and he was forced to return impotent to Brest before anything had been accomplished. The allies were not able to take the sea again that campaign, but even had it been in their power to do so, Hardy and Kempenfelt could have played their defensive game indefinitely, and with ever-increasing chances, as the winter drew near, of dealing a paralysing blow.
There was never any real chance of success, though it is true Dumouriez thought otherwise. He believed the enterprise might have gone through if a diversion had been made by the bulk of the fleet against Ireland, and under cover of it a coup de main delivered upon the Isle of Wight, "for which," he said, "six or eight of the line would have been enough." But it is inconceivable that old hands like Hardy and Kempenfelt would have been so easily beguiled of their hold on the line of passage. Had such a division been detached up the Channel from the allied fleet they would surely, according to tradition, have followed it with either a superior force or their whole squadron.
The well-known projects of the Great War followed the same course. Under Napoleon's directions they ran the whole gamut of every scheme that ever raised delusive hope before. Beginning from the beginning with the idea of stealing his army across in flat-boats, he was met with the usual flotilla defence. Then came his only new idea, which was to arm his transport flotilla to the point of giving it power to force a passage for itself. We replied by strengthening our flotilla. Convinced by experiment that his scheme was now impracticable, he set his mind on breaking the blockade by the sudden intrusion of a flying squadron from a distance. To this end various plausible schemes were worked out, but plan after plan melted in his hand, till he was forced to face the inevitable necessity of bringing an overwhelming battle force up to his transports. The experience of two centuries had taught him nothing. By a more distant concentration than had ever been attempted before he believed he could break the fatal hold of his enemy. The only result was so severely to exhaust his fleet that it never could get within reach of the real difficulties of its task, a task which every admiral in his service knew to be beyond the strength of the Imperial Navy. Nor did Napoleon even approach a solution of the problem he had set himself—invasion over an uncommanded sea. With our impregnable flotilla hold covered by an automatic concentration of battle-squadrons off Ushant, his army could never even have put forth, unless he had inflicted upon our covering fleet such a defeat as would have given him command of the sea, and with absolute control of the sea the passage of an army presents no difficulties.
Of the working of these principles under modern conditions we have no example. The acquisition of free movement must necessarily modify their application, and since the advent of steam there have been only two invasions over uncommanded seas—that of the Crimea in 1854, and that of Manchuria in 1904—and neither of these cases is in point, for in neither was there any attempt at naval defence. Still there seems no reason to believe that such defence applied in the old manner would be less effective than formerly. The flotilla was its basis, and since the introduction of the torpedo the power of the flotilla has greatly increased. Its real and moral effect against transports must certainly be greater than ever, and the power of squadrons to break a flotilla blockade is more restricted. Mines, again, tell almost entirely in favour of defence, so much so indeed as to render a rapid coup de main against any important port almost an impossibility. In the absence of all experience it is to such theoretical considerations we must turn for light.
Theoretically stated, the success of our old system of defence depended on four relations. Firstly, there is the relation between the rapidity with which an invasion force could be mobilised and embarked, and the rapidity with which restlessness in foreign ports and places d'armes could be reported; that is to say, the chance of surprise and evasion are as the speed of preparation to the speed of intelligence.
Secondly, there is the relation of the speed of convoys to the speed of cruisers and flotilla; that is to say, our ability to get contact with a convoy after it has put to sea and before the expedition can be disembarked is as the speed of our cruisers and flotilla to the speed of the convoy.
Thirdly, there is the relation between the destructive power of modern cruisers and flotillas against a convoy unescorted or weakly escorted and the corresponding power in sailing days.
Fourthly, there is the relation between the speed of convoys and the speed of battle-squadrons, which is of importance where the enemy's transports are likely to be strongly escorted. On this relation depends the facility with which the battle-squadron covering our mobile defence can secure an interior position from which it may strike either the enemy's battle-squadron if it moves or his convoy before it can complete its passage and effect the landing.
All these relations appear to have been modified by modern developments in favour of the defence. In the first ratio, that of speed of mobilisation to speed of intelligence, it is obviously so. Although military mobilisation may be still relatively as rapid as the mobilisation of fleets, yet intelligence has outstripped both. This is true both for gaining and for conveying intelligence. Preparations for oversea invasion were never easy to conceal, owing to the disturbance of the flow of shipping that they caused. Elaborate precautions were taken to prevent commercial leakage of intelligence, but they never entirely succeeded. Yet formerly, in the condition of comparative crudeness with which international trade was then organised, concealment was relatively easy, at least for a time. But the ever-growing sensitiveness of world-wide commerce, when market movements are reported from hour to hour instead of from week to week, has greatly increased the difficulty. And apart from the rapidity with which information may be gathered through this alert and intimate sympathy between Exchanges, there is the still more important fact that with wireless the speed of conveying naval intelligence has increased in a far higher ratio than the speed of sea transit.
As regards the ratio between cruiser and convoy speeds, on which evasion so much depends, it is the same. In frigate days the ratio appears to have been not more than seven to five. Now in the case at any rate of large convoys it would be nearly double.
Of the destructive power of the flotilla, growing as it does from year to year, enough has been said already. With the advent of the torpedo and submarine it has probably increased tenfold. In a lesser degree the same is true of cruisers. In former days the physical power of a cruiser to injure a dispersing convoy was comparatively low, owing to her relatively low excess of speed and the restricted range and destructive power of her guns. With higher speed and higher energy and range in gun power the ability of cruisers to cut up a convoy renders its practical annihilation almost certain if once it be caught, and consequently affords a moral deterrent against trusting to evasion beyond anything that was known before.
The increased ratio of battle-fleet speed to that of large convoys is equally indisputable and no less important, for the facility of finding interior positions which it implies goes to the root of the old system. So long as our battle-fleet is in a position whence it can cover our flotilla blockade or strike the enemy's convoy in transit, it forces his battle-fleet in the last resort to close up on the convoy, and that, as Kempenfelt pointed out, is practically fatal to the success of invasion.
From whatever point of view, then, we regard the future chances of successful invasion over an uncommanded sea, it would seem that not only does the old system hold good, but that all modern developments which touch the question bid fair to intensify the results which our sea service at least used so confidently to expect, and which it never failed to secure.
II. ATTACK AND DEFENCE OF TRADE
The base idea of the attack and defence of trade may be summed up in the old adage, "Where the carcase is, there will the eagles be gathered together." The most fertile areas always attracted the strongest attack, and therefore required the strongest defence; and between the fertile and the infertile areas it was possible to draw a line which for strategical purposes was definite and constant. The fertile areas were the terminals of departure and destination where trade tends to be crowded, and in a secondary degree the focal points where, owing to the conformation of the land, trade tends to converge. The infertile areas were the great routes which passed through the focal points and connected the terminal areas. Consequently attack on commerce tends to take one of two forms. It may be terminal or it may be pelagic, terminal attack being the more profitable, but demanding the greater force and risk, and pelagic attack being the more uncertain, but involving less force and risk.
These considerations lead us directly to the paradox which underlies the unbroken failure of our enemies to exercise decisive pressure upon us by operations against our trade. It is that where attack is most to be feared, there defence is easiest. A plan of war which has the destruction of trade for its primary object implies in the party using it an inferiority at sea. Had he superiority, his object would be to convert that superiority to a working command by battle or blockade. Except, therefore, in the rare cases where the opposed forces are equal, we must assume that the belligerent who makes commerce destruction his primary object will have to deal with a superior fleet. Now, it is true that the difficulty of defending trade lies mainly in the extent of sea it covers. But, on the other hand, the areas in which it tends to congregate, and in which alone it is seriously vulnerable, are few and narrow, and can be easily occupied if we are in superior force. Beyond those areas effective occupation is impossible, but so also is effective attack. Hence the controlling fact of war on commerce, that facility of attack means facility of defence.
Beside this fundamental principle we must place another that is scarcely less important. Owing to the general common nature of sea communications, attack and defence of trade are so intimately connected that the one operation is almost indistinguishable from the other. Both ideas are satisfied by occupying the common communications. The strongest form of attack is the occupation of the enemy's terminals, and the establishment of a commercial blockade of the ports they contain. But as this operation usually requires the blockade of an adjacent naval port, it also constitutes, as a rule, a defensive disposition for our own trade, even when the enemy's terminal area does not overlap one of our own. In the occupation of focal areas the two ideas are even more inseparable, since most, if not all, such areas are on lines of communication that are common. It will suffice, therefore, to deal with the general aspect of the subject from the point of view of defence.
It was in conformity with the distinction between fertile and infertile areas that our old system of trade defence was developed. Broadly speaking, that system was to hold the terminals in strength, and in important cases the focal points as well. By means of a battle-squadron with a full complement of cruisers they were constituted defended areas, or "tracts" as the old term was, and the trade was regarded as safe when it entered them. The intervening trade-routes were left as a rule undefended. Thus our home terminals were held by two battle-squadrons, the Western Squadron at the mouth of the Channel, and the North Sea or Eastern Squadron with its headquarters usually in the Downs. To these was added a cruiser squadron on the Irish station based at Cork, which was sometimes subordinate to the Western Squadron and sometimes an independent organisation. The area of the Western Squadron in the French wars extended, as we have seen, over the whole Bay of Biscay, with the double function, so far as commerce was concerned, of preventing the issue of raiding squadrons from the enemy's ports, and acting offensively against his Atlantic trade. That of the North Sea squadron extended to the mouth of the Baltic and the north-about passage. Its main function during the great naval coalitions against us was to check the operations of Dutch squadrons or to prevent the intrusion of French ones north-about against our Baltic trade. Like the Western Squadron, it threw out divisions usually located at Yarmouth and Leith for the protection of our coastwise trade from privateers and sporadic cruisers acting from ports within the defended area. Similarly, between the Downs and the Western Squadron was usually one or more smaller squadrons, mainly cruisers, and generally located about Havre and the Channel Islands, which served the same purpose for the Norman and North Breton ports. To complete the system there were flotilla patrols acting under the port admirals and doing their best to police the routes of the coastwise and local traffic, which then had an importance long since lost. The home system of course differed at different times, but it was always on these general lines. The naval defence was supplemented by defended ports of refuge, the principal ones being on the coast of Ireland to shelter the ocean trade, but others in great numbers were provided within the defended areas against the operations of privateers, and the ruins of batteries all round the British shores testify how complete was the organisation.
A similar system prevailed in the colonial areas, but there the naval defence consisted normally of cruiser squadrons stiffened with one or two ships-of-the-line mainly for the purpose of carrying the flag. They were only occupied by battle-squadrons when the enemy threatened operations with a similar force. The minor or interior defence against local privateers was to a large extent local; that is, the great part of the flotilla was furnished by sloops built or hired on the spot, as being best adapted for the service.
Focal points were not then so numerous as they have become since the development of the Far Eastern trade. The most important of them, the Straits of Gibraltar, was treated as a defended area. From the point of view of commerce-protection it was held by the Mediterranean squadron. By keeping watch on Toulon that squadron covered not only the Straits, but also the focal points within the sea. It too had its extended divisions, sometimes as many as four, one about the approaches to Leghorn, one in the Adriatic, a third at Malta, and the fourth at Gibraltar. In cases of war with Spain the latter was very strong, so as to secure the focal area against Cartagena and Cadiz. On one occasion indeed, in 1804-5, as we have seen, it was constituted for a short time an independent area with a special squadron. But in any case the Gibraltar area had its own internal flotilla guard under the direction of the port admiral as a defence against local privateers and pirates.
The general theory of these defended terminal and focal areas, it will be seen, was to hold in force those waters which converging trade made most fertile, and which therefore furnished an adequate field for the operations of raiding squadrons. In spite of the elaborate defensive system, such squadrons might, and sometimes did, intrude by surprise or stealth, and were then able to set at defiance both convoy escorts and the cruiser outposts. But, as experience proved, the system of terminal defence by battle-squadrons made it impossible for such raiding squadrons to remain long enough on the ground to cause any serious interruption or to do serious harm. It was only by a regular fleet of superior strength that the system could be broken down. In other words, the defence could only fall when our means of local control was destroyed by battle.
So much for the defended areas. With regard to the great routes that connected them, it has been said they were left undefended. By this is meant that the security of ships passing along them was provided for, not by patrols but by escort. The convoy system was adopted, and the theory of that system is that while vessels are on the great routes they are normally liable only to sporadic attack, and they are consequently collected into fleets and furnished with an escort sufficient to repel sporadic attack. In theory, cruiser escort is sufficient, but in practice it was found convenient and economical to assign the duty in part to ships-of-the-line which were going out to join the distant terminal squadron or returning from it for a refit or some other reason; in other words, the system of foreign reliefs was made to work in with the supplementary escort system. Where no such ships were available and the convoys were of great value, or enemy's ships-of-the-line were known to be out, similar units were specially detailed for convoy duty to go and return, but this use of battle units was exceptional.
Such a method of dealing with the great routes is the corollary of the idea of defended areas. As those areas were fertile and likely to attract raiding squadrons, so the great routes were infertile, and no enemy could afford to spend squadrons upon them. It is obvious, however, that the system had its weak side, for the mere fact that a convoy was upon a great route tended to attract a squadron, and the comparative immunity of those routes was lost. The danger was provided for to a great extent by the fact that the enemy's ports from which a squadron could issue were all within defended areas and watched by our own squadrons. Still, the guard could not be made impenetrable. There was always the chance of a squadron escaping, and if it escaped towards a critical trade-route, it must be followed. Hence there were times when the convoy system seriously disturbed our dispositions, as, for instance, in the crisis of the Trafalgar campaign, when for a short time our chain of defended areas was broken down by the escape of the Toulon squadron. That escape eventually forced a close concentration on the Western Squadron, but all other considerations apart, it was felt to be impossible to retain the mass for more than two days owing to the fact that the great East and West Indies convoys were approaching, and Villeneuve's return to Ferrol from Martinique exposed them to squadronal attack. It was, in fact, impossible to tell whether the mass had not been forced upon us with this special end in view.
In the liability to deflection of this kind lay the most serious strategical objection to the convoy system. It was sought to minimise it by giving the convoys a secret route when there was apprehension of squadronal interference. It was done in the case just cited, but the precaution seemed in no way to lessen the anxiety. It may have been because in those days of slow communication there could be no such certainty that the secret route had been received as there would be now.
Modern developments and changes in shipping and naval material have indeed so profoundly modified the whole conditions of commerce protection, that there is no part of strategy where historical deduction is more difficult or more liable to error. To avoid such error as far as possible, it is essential to keep those developments in mind at every step. The more important of them are three in number. Firstly, the abolition of privateering; secondly, the reduced range of action for all warships; and thirdly, the development of wireless telegraphy. There are others which must be dealt with in their place, but these three go to the root of the whole problem.