no fortifications of any imagined technical perfection, can avert national ruin; these are the cardinal principles of Imperial Defence.

Yet these cardinal principles are now once more being impugned on the highest military authoritythat of the great soldier whose long and brilliant career, whose lofty and disinterested patriotism, whose splendid achievements in India and South Africa, have endeared him to every Englishman, and have invested him with a right to speak on all questions of national defence which no one would presume to dispute, least of all a mere civilian student like myself. I have said, "on all questions of national defence." But the fact remains that, for an insular Power like England -a Power which can neither attack its enemies nor be attacked by them except across the sea-no question of national defence can ever be either a purely military question or a purely naval question. Lord Roberts is a soldier; one of the greatest of living soldiers. On the military issues involved in any large question of national defence, I, for one, should never dream of disputing his authority; but on the naval issues involved in the same question, I would point out, with all respect, that, apart from his immense personal prestige, his authority is not in kind greater than that of any other amateur student of the subject. He is not an expert in the theory and practice of naval warfare any more than I am myself. In that respect he and I stand on the same footing, if I may say so without presumption, and on that ground alone do I venture to dispute some of the premisses he has lately advanced in respect of the naval aspects of the question of invasion.

Now I understand the school of which Lord Roberts is the illustrious leader to contend that we cannot rely on naval force alone, however superior to that of the supposed enemy, to prevent an invader landing on these shores in such force as, in the present condition of our military defences, might afford the

enemy a reasonable prospect of bringing us to submission. The incapacity of the Navy to "impeach the invader on the sea is thus represented as due, not to any deficiency of strength at any given point or moment, but to some indefeasible defect inherent in the nature of naval force as such and in the nature of the element on which it operates. If it were due to a mere deficiency of naval strength, the obvious and infallible remedy would seem to be to make good that deficiency at any cost and with as little delay as possible. But that is not the remedy recommended by Lord Roberts and his school. They would forthwith increase, and very largely increase, the military forces of the Crown available for the defence of these shores. At the risk of seeming presumptuous, I must insist once more that, if the sailors are to be trusted in a matter which especially concerns their profession, this is emphatically the wrong way to go to work. I do not here pose as an adherent of what is called, for some reason never intelligible to me, the "Blue Water School." I have never willingly used that phrase, for frankly, I do not in the least know what it means. I have learnt from the sailors that the function of a naval force adequate to prevent invasion is to operate neither in the blue waters of the Atlantic or the Mediterranean as such, nor in the grey waters of the North Sea as such, but in all those waters, whether blue or grey, whether deep or shallow, from which any menace of invasion can, on any reasonable calculation of contingencies, be expected to come. But I am an adherent as I have said, a convinced and wholly unrepentant adherent-of what I would call the "naval" school, the school, that is, that holds as the cardinal principle of its creed, that with a sufficiency of naval force the invader can and will be impeached at sea, and that without a sufficiency of naval force he cannot be impeached at all. Am I then an adherent of what has been called-merely pour rire perhaps― the "dinghy" school, the school which is supposed

to hold, though I never met a disciple of it, that not a dinghy full of foreign soldiers could ever land on these shores so long as our naval defence on the seas is sufficient? By no manner of means. I hold what is now the official doctrine as quite recently expounded in Parliament by the Secretary of State for War that the military forces of the Crown available for home defence should at all times be sufficient in numbersand, of course, efficient enough in training, equipment, and organization-to compel any enemy who projects an invasion of this country to come in such force that he cannot come by stealth. Of course I presuppose an effective command by this country of the seas to be traversed by the invader; but that is not to beg the question. It surely must be common ground with all disputants in this controversy that this country must never surrender the command of the sea to its enemies. That is the very meaning of the naval supremacy at which we aim, and must always aim as a condition absolutely indispensable to our national security and our Imperial integrity. If there is any room for doubt, or even for any reasonable feeling of insecurity, on this vital point, the one and only way to remove it is instantly to set about increasing our naval forces to any extent that may be necessary to re-establish our imperilled supremacy at sea. If I entertained any such doubt, I would not add a single man to the Army until I had once more brought the Navy to its required strength of unchallengeable supremacy at sea. For I hold now, as I held with Sir George Clarke twelve years ago, that if the sea communications of the Empire are not securely held in war, "no army of any assigned magnitude, and no fortifications of any imagined technical perfection can avert national ruin."

Now I do not attempt to determine either the numbers of the military forces that must be available for home defence, nor the character of the training, equipment, and organization that ought to be given

PREFACE

xvii to them if they are to discharge the function that I have assigned to them; that I leave entirely to competent military experts of whom assuredly I am not one. Neither am I a naval expert, for I hold that none but sailors are entitled to be so called; but I know what the sailors think, for, as I am about to show, we have it on official record. Is it too much to ask the soldiers to withdraw from the naval province, in which they are not experts, and to confine themselves to the military province in which their authority is no more to be disputed than that of the sailors is in their province? There are, indeed, some sailors whose authority I, at least, have no title to dispute, who follow the lead of Lord Roberts. But I suspect they do so mainly on the ground that they hold "national service" of the character advocated by him to be a good thing in itself, rather than on the assumption which his main argument presupposes, namely, that no sufficiency of naval force can insure this country from invasion. I repeat that his main argument must rest on that assumption, because, if mere insufficiency of naval force were alleged, the plain logic of the situation would imperatively insist that any and every such alleged insufficiency should be made good before any other form of national defence were even so much as attempted. But this will not serve the turn of Lord Roberts and his school. Soldiers, and the disciples of soldiers themselves, they insist on telling the sailor and his disciples that, whatever they may think to the contrary, no sufficiency of naval force can insure this country against invasion. I, of course, am no sailor, and therefore it is not for me to answer them. They, on the other hand, albeit experts, and experts not to be challenged by me at any rate, in their own province, are just as little experts in the sailors' province as I am. Fortunately there exists a tribunal, composed largely of experts in both provinces, to which we can both appeal. That tribunal is the Committee of Imperial Defence as constituted by Mr.

b

Balfour. One of the first problems to which the Committee of Imperial Defence addressed itself was that of invasion, its risks and its possibilities, and some four years ago, on May 11, 1905, Mr. Balfour expounded in the House of Commons the conclusions it had then reached. In unfolding his exposition he said:

Though every one must recognize that this is the central problem of Imperial and national defence, we see year by year the continuance of a profitless wrangle between the advocates of different schools of military and naval thought to which the puzzled civilian gives a perplexed attention, and which leaves in the general mind an uneasy sense that, in spite of the millions we are spending on the Navy and the Army, the country is not, after all, secure against some sudden onslaught which might shatter the fabric of Empire. This, be it remembered, is no new state of things. It reaches far back into a historic past. The same controversy in which we are now engaged was raging in the time of Drake; and then, as now, it was in the main the soldiers who took one side; in the main, the sailors who took the other. The great generals in the sixteenth century believed the invasion of England possible, the great admirals did not believe it possible. If you go down the stream of time, you come to an exactly similar state of things during the Napoleonic wars. . . . It is certain that Napoleon believed invasion to be possible; and it is equally certain that Nelson believed it to be impossible. Forty years later you find the Duke of Wellington, in a very famous letter, expressing, in terms almost pathetic in their intensity, his fears of invasion-fears which naval opinion has never shared, provided our fleets be adequate. We found, when we took up the subject, that the perennial dispute was still unsettled; and it appeared to us-I do not say that full agreement could be come to, but something nearer than ever had been reached before-if we could avoid barren generalities, and devise a concrete problem capable of definite solution, yet based on suppositions so unfavourable to this country, that if, in this hypothetical case, serious invasion was demonstrably impossible, we