It has been seen how, as a result of the struggle with Napoleon, England, from 1805 onwards, was the only sea power remaining in Europe, and indeed, with the exception of the United States, the only sea power in the world. One of the results was that she had for many years the monopoly of the whole ocean, not merely for the purposes of war, but also for the purposes of trade. The British mercantile marine continued through the greater part of the nineteenth century to increase its preponderance over all others, and this remarkable, and probably quite exceptional, growth was greatly favoured by the Civil War in America, during which the mercantile marine of the United States received from the action of the Confederate cruisers a damage from which it has never recovered.

In the years immediately following 1805, Great Britain in self-defence, or as a means of continuing the war against France, in regard to which her resources for operations on land were limited, had recourse to the operations of blockade, by which the sea was closed, as far as possible, to enemy merchantmen while Great Britain prohibited neutral ships from carrying enemy goods. Napoleon replied by the attempt to exclude British goods from the Continent altogether, and indeed the pressure produced by Great Britain's blockades compelled Napoleon further to extend his domination on the Continent. Thus the other continental States found themselves between the devil and the deep sea. They had to submit to the domination of Napoleon on land and to the complete ascendency of Great Britain on the waters which surrounded their coasts. The British claims to supremacy at sea were unanimously resented by all the continental States, which all suffered from them, but in all cases the national resentment against French invasion or French occupation of territory was greater than the resentment against the invisible pressure exercised by the British navy. In the wars of liberation, though Great Britain was the welcome ally of all the States that were fighting against France, the pressure of British sea power was none the less disagreeable and, in the years of peace which followed, the British monopoly of sea power, of sea-carriage, of manufacturing industry, and of international trade were equally disliked by almost all the nations of Europe. Protective duties were regarded as the means of fostering national industries and of sheltering them against the overpowering competition of British manufactures. The British claim to the dominion of the sea was regarded as unfounded in right, and was in principle as strongly denounced as had been the territorial domination of France. The mistress of the seas was regarded as a tyrant, whom it would be desirable, if it were possible, to depose, and there were many who thought that as the result of a conflict in which the final success had been gained by the co-operation of a number of States acting together, the gains of Great Britain which, as time went on, were seen to be growing into a world-wide empire, had been out of proportion to the services she had rendered to the common cause.

Meantime during the century which has elapsed since the last great war, there has been a complete change in the conditions of intercourse between nations at sea and of maritime warfare. It has come about gradually, almost imperceptibly, so that it could hardly be appreciated before the close of the nineteenth century. But it is vital to Great Britain that her people should understand the nature of the transformation.

The first thing to be observed is that the British monopoly of shipping and of oversea trade has disappeared. Great Britain still has by far the largest mercantile marine and by far the greatest share in the world's sea traffic, but she no longer stands alone. Germany, the United States, France, Norway, Italy, and Japan all have great fleets of merchant ships and do an enormous, some of them a rapidly increasing, seaborne trade. A large number of the principal States import the raw material of manufacture and carry on import and export on a large scale. The railway system connects all the great manufacturing centres, even those which lie far inland, with the great ports to and from which the lines of steamers ply. The industrial life of every nation is more than ever dependent upon its communications with and by the sea, and every nation has become more sensitive than ever to any disturbance of its maritime trade. The preponderance of the British navy is therefore a subject of anxiety in every State which regards as possible a conflict of its own interests with those of Great Britain. This is one of the reasons why continental States have during the last quarter of a century been disposed to increase their fleets and their naval expenditure.

In the Declaration of Paris, renewed and extended by the Declaration of London, the maritime States have agreed that in any future war enemy goods in a neutral ship are to be safe from capture unless the ship is running a blockade, which must be effective. Whether Great Britain was well or ill advised in accepting this rule is a question which it is now useless to discuss, for the decision cannot be recalled, and the rule must be regarded as established beyond controversy. Its effect is greatly to diminish the pressure which a victorious navy can bring to bear upon a hostile State. It deprives Great Britain of one of the most potent weapons which she employed in the last great war. To-day it would be impracticable even for a victorious navy to cut off a continental State from seaborne traffic. The ports of that State might be blockaded and its merchant ships would be liable to capture, but the victorious navy could not interfere with the traffic carried by neutral ships to neutral ports. Accordingly, Great Britain could not now, even in the event of naval victory being hers, exercise upon an enemy the pressure which she formerly exercised through the medium of the neutral States. Any continental State, even if its coasts were effectively blockaded, could still, with increased difficulty, obtain supplies both of raw material and of food by the land routes through the territory of its neutral neighbours. But Great Britain herself, as an insular State, would not, in case of naval defeat, have this advantage. A decisive defeat of the British navy might be followed by an attempt on the part of the enemy to blockade the coasts of Great Britain, though that would no doubt be difficult, for a very large force would be required to maintain an effective blockade of the whole coast-line.

It is conceivable that an enemy might attempt in spite of the Declaration of London to treat as contraband food destined for the civil population and this course ought to be anticipated, but in the military weakness of Great Britain an enemy whose navy had gained the upper hand would almost certainly prefer to undertake the speedier process of bringing the war to an end by landing an army in Great Britain. A landing on a coast so extensive as that of this island can with difficulty be prevented by forces on land, because troops cannot be moved as quickly as ships.

The war in the Far East has shown how strong such an army might be, and how great a military effort would be needed to crush it. The proper way to render an island secure, is by a navy strong enough to obtain in war the control of the surrounding sea, and a navy unable to perform that function cannot be regarded as a guarantee of security.

The immediate effects of naval victory can hardly ever again be so far-reaching as they were a century ago in the epoch of masts and sails. At that time there were no foreign navies, except in European waters, and in the Atlantic waters of the United States. When, therefore, the British navy had crushed its European adversaries, its ships could act without serious opposition upon any sea and any coast in the world. To-day, the radius of action of a victorious fleet is restricted by the necessity of a supply of coal, and therefore by the secure possession of coaling-stations at suitable intervals along any route by which the fleet proposes to move, or by the goodwill of neutrals in permitting it to coal at their depots. To-day, moreover, there are navies established even in distant seas. In the Pacific, for example, are the fleets of Japan and of the United States, and these, in their home waters, will probably be too strong to be opposed by European navies acting at a vast distance from their bases.

It seems likely, therefore, that neither Great Britain nor any other State will in future enjoy that monopoly of sea power which was granted to Great Britain by the circumstances of her victories in the last great war. What I have called the great prize has in fact ceased to exist, and even if an adversary were to challenge the British navy, the reward of his success would not be a naval supremacy of anything like the kind or extent which peculiar conditions made it possible for Great Britain to enjoy during the nineteenth century. It would be a supremacy limited and reduced by the existence of the new navies that have sprung up.

From these considerations a very important conclusion must be drawn. In the first place, enough victory at sea is in case of war as indispensable to Great Britain as ever, for it remains the fundamental condition of her security, yet its results can hardly in future be as great as they were in the past, and in particular it may perhaps not again enable her to exert upon continental States the same effective pressure which it formerly rendered possible.

In order, therefore, to bring pressure upon a continental adversary, Great Britain is more than ever in need of the co-operation of a continental ally. A navy alone cannot produce the effect which it once did upon the course of a land war, and its success will not suffice to give confidence to the ally. Nothing but an army able to take its part in a continental struggle will, in modern conditions, suffice to make Great Britain the effective ally of a continental State, and in the absence of such an army Great Britain will continue to be, as she is to-day, without continental allies.

A second conclusion is that our people, while straining every nerve in peace to ensure to their navy the best chances of victory in war, must carefully avoid the conception of a dominion of the sea, although, in fact, such a dominion actually existed during a great part of the nineteenth century. The new conditions which have grown up during the past thirty years have made this ideal as much a thing of the past as the medifval conception of a Roman Empire in Europe to whose titular head all kings were subordinate.