But first of all, to clear away one obscurity—Invasion was not our problem; Defence was our problem; for the greater included the less.
The word 'defence' is apt to carry different meanings to different minds. The best defence of England and British interests, at any given time, may or may not consist in keeping our main army in the United Kingdom and waiting to be attacked here. It all depends upon the special circumstances of each case. The final decision must be governed by one consideration, and one only—how to strike the speediest, heaviest, and most disabling blow at the aggressor. If by keeping our army in England and endeavouring to lure the enemy into our toils, that end is most likely to be accomplished, then it is obviously best to keep our army here. If by sending it into the north of France to combine with the French the supreme military object has a superior chance of being achieved, then it is best to send it into the north of France.
A defensive war cannot be defined and circumscribed as a war to drive out invaders, or even to prevent the landing of invaders. The best way to defend your castle may be to man the walls, to fall upon the enemy at the ford, to harry his lands, or even to attack him in his castle. There is no fixed rule. The circumstances in each case make the rule.
CO-OPERATION WITH FRANCE
A war is not less a defensive war if you strike at your enemy in his own territory, or if you come to the aid of your ally, whose territory has been invaded or is threatened. In the circumstances which prevailed for a considerable number of years prior to the outbreak of the present war, it gradually became more and more obvious, that our soundest defence would be joint action with France upon her north-eastern frontier. For there, beyond any doubt, would Germany's supreme effort be made against the Triple Entente. If the attack failed at that point, it would be the heaviest and most disabling blow which our enemy could suffer. If, on the other hand, it succeeded, France and England would have to continue the struggle on terms immensely less favourable.
This opinion was not by any means unanimously or clearly held; but during the summer of 1911 and subsequently, it was undoubtedly the hypothesis upon which those members of our Government relied, who were chiefly responsible for the conduct of foreign affairs. Unfortunately Parliament and the country had never accepted either the policy or its consequences; they had never been asked to accept either the one or the other; nor had they been educated with a view to their acceptance.
At that time the error was exceedingly prevalent, that it is a more comfortable business fighting in your own country than in somebody else's. From this it followed that it would be folly to engage in what were termed disapprovingly 'foreign adventures,' and that we should be wise to await attack behind our own shores. Recent events have wrought such a complete and rapid conversion from this heresy, that it is no longer worth while wasting words in exposing it. It is necessary, however, to recall how influential this view of the matter was, not only up to the declaration of war, but even for some time afterwards.
As to the precise form of co-operation between the members of the Triple Entente in case of war, there could be no great mystery. It was obvious to any one who paid attention to what happened during the summer and autumn of 1911, that in the event of Germany attacking France over the Agadir dispute, we had let it be understood and expected, that we should send our Expeditionary Force across the Channel to co-operate with the French army on the north-eastern frontier.
[[1]] It can hardly be overlooked, however, that this principle, rightly or wrongly interpreted, had something to do with the Crimean War (1854-56) and with the British attitude at the Congress of Berlin (1878).