In war the British Navy has three prominent duties to discharge.  It has to protect our maritime trade, to keep open the communications between the different parts of the empire, and to prevent invasion.  If we command the sea these duties will be discharged effectually.  As long as we command the sea the career of hostile cruisers sent to prey on our commerce will be precarious, because command of the sea carries with it the necessity of possessing an ample cruiser force.  As long as the condition mentioned is satisfied our ocean communications will be kept open, because an inferior enemy, who cannot obtain the command required, will be too much occupied in seeing to his own safety to be able to interfere seriously with that of any part of our empire.  This being so, it is evident that the greater operation of invasion cannot be attempted, much less carried to a successful termination, by the side which cannot make head against the opposing fleet.  Command of the sea is the indispensable preliminary condition of a successful military expedition sent across the water.  It enables the nation which possesses it to attack its foes where it pleases and where they seem to be most vulnerable.  At the same time it gives to its possessor security against serious counter-attacks, and affords to his maritime commerce the most efficient protection that can be devised.  It is, in fact, the main object of naval warfare.

III

WAR AND ITS CHIEF LESSONS[58]

[Footnote 58:  Written in 1900. (NavalAnnual_, 1901.)]

Had the expression ‘real war’ been introduced into the title of this chapter, its introduction would have been justifiable.  The sources—­if not of our knowledge of combat, at least of the views which are sure to prevail when we come to actual fighting—­are to be found in two well-defined, dissimilar, and widely separated areas.  Within one are included the records of war; within the other, remembrance of the exercises and manoeuvres of a time of peace.  The future belligerent will almost of a certainty have taken a practical part in the latter, whilst it is probable that he will have had no personal experience of the former.  The longer the time elapsed since hostilities were in progress, the more probable and more general does this absence of experience become.  The fighting man—­that is to say, the man set apart, paid, and trained so as to be ready to fight when called upon—­is of the same nature as the rest of his species.  This is a truism; but it is necessary to insist upon it, because professional, and especially professorial, strategists and tacticians almost invariably ignore it.  That which we have seen and know has not only more, but very much more, influence upon the minds of nearly all of us than that of which we have only heard, and, most likely, heard but imperfectly.  The result is that, when peace is interrupted and the fighting man—­on both sea and land—­is confronted with the problems of practical belligerency, he brings to his attempts at their solution an intellectual equipment drawn, not from knowledge of real war, but from the less trustworthy arsenal of the recollections of his peace training.