As between the two nations, France and Germany, it would be natural for the stronger to be left to take the offensive and invade the weaker. Four or five marches from the frontier the task of the invader becomes very difficult and may be made more difficult still. The defenders have superior communications from flank to flank and from front to rear; they fall back on carefully-chosen, well-prepared positions and on ample magazines of munitions and supplies. The invader finds himself in a hostile country, surrounded by spies, with bridges and roads, especially lateral roads, broken and disorganised, and important junctions defended by fortresses still in the hands of the enemy. He is thus forced to deliver the first great battle on ground selected and prepared by his opponent. It is surely at this moment, and after this first shock has been sustained under the best conditions, that the opportunity for the offensive energy of the weaker Power presents itself.
If the Germans invaded France it seemed to me in those days that the French would be wise to act as follows:—
They should entrench themselves conveniently along or near their frontier, constructing a vast system of field fortifications, open and concealed, sham and real, according to every device known at that time; and in these positions they should await the first shock of the Germans. I believed that the Germans did not appreciate the tremendous power of modern weapons, particularly the rifle. I based this on what I had seen of their methods in their manœuvres of 1906 and 1909 and on what I had learned about rifle fire in the South African War. The Germans were the challengers; they were the stronger, but not, in my opinion, strong enough for the continuous storming and reduction of well-fortified positions held by French regular armies or by British troops. I did not, of course, contemplate that the French would dig one uniform line along the whole length of their frontier. They would naturally treat the problem selectively, here resisting with their utmost strength, there allowing the enemy to penetrate and bulge into unpromising country or into some well-considered tactical area only to be brought up by lines fifteen to twenty miles in rear. They would not hesitate to sell the Germans piece by piece a certain amount of ground for disproportionate losses. The universal tactical object to be pursued in this first phase should be to force the Germans to expose themselves in the open to the rifle and artillery fire of well-trained Frenchmen.
It would be reasonable to hope that a process of this kind, continued for three or four days along the whole front, would have resulted in far heavier losses to the Germans than to the French, and that a larger proportion of the German than of the French armies would have been deployed and extended. One hoped in this way to see the French take toll of the manhood of the German nation at the outset of the war, as the British Army did on a small scale at Mons and Le Cateau. This would in no way have excluded tactical action by means of counter-attacks wherever opportunities presented themselves. Meanwhile at least two-fifths of the French armies should have been held back in a great mass of manœuvre, north-east of Paris. With this mass of manœuvre I hoped the British Army would have been associated. This general disposition should not have been compromised by any effort to proceed to the relief of Belgium, except with cavalry and small detachments to encourage the Belgians and to gain time. I was, of course, firmly persuaded, in common with the British General Staff, that the main German encircling movement would take place through Belgium and would comprise considerable forces west of the Belgian Meuse. I hoped that if this movement eventuated and prolonged itself in great strength, the French would find an opportunity of using the greater part of their armies of manœuvre against it after the Germans had been well punished along the whole front. At any rate, that is the sort of way in which I thought then, before the event, and think still, the French Command might best have safeguarded the vital interests of France.
Very different, however, were the ideas of General Joffre. The famous ‘Plan XVII’ consisted in a general offensive in an easterly and north-easterly direction by four French armies, with the last remaining army in reserve behind their centre. It was based upon an ardent faith that the French right would penetrate deeply into Alsace and Lorraine and an obstinate disbelief that the French left would be turned by a German movement west of the Meuse through Belgium. Both these calculations were to be completely falsified by the first events of the war. From the very earliest days it was clear that the views which the British General Staff had consistently held, since 1911, of a great German turning movement through Belgium, probably on both sides of the Belgian Meuse, were correct. Why should the Germans with their eyes open throw first Belgium and then the British Empire into the scales against them unless for an operation of supreme magnitude? Besides, there were the evidences of their long preparations—camps, railways and railway sidings—which the British Staff under Sir John French and Sir Henry Wilson had so minutely studied. Lastly, reported with much accuracy from day to day, there came the enormous troop movements on the German right, towards and into Belgium on both sides of the Meuse. Before the end of the first week in August General Lanrezac, the Commander of the left French Army (the Fifth), was raising loud cries of warning and alarm about the menace to his left, and indeed his rear, if he carried out the rôle assigned to him and attacked as ordered in a north-easterly direction. By the end of the second week the presence of the accumulating masses of the German right could no longer be denied by the French High Command, and certain measures, tardy and inadequate, were taken to cope with it. Nevertheless, after the raid of a corps and a cavalry division into Alsace on the 13th August, General Joffre began his offensive into Lorraine with the two armies of the French right, the centre armies conforming a few days later; and up till the evening of the 18th General Lanrezac and the left French army were still under orders to advance north-east. Three days later this same army was defending itself in full battle from an attack from the north and north-west. It had been compelled to make a complete left wheel. The main shock began on the 20th, when the two armies of the French right battered themselves in vain against the strongly-prepared German defences. By the 21st the French centre armies were definitely stopped, and by noon on the 23rd General Lanrezac and the French army of the left were outflanked and beaten. Meanwhile our small army, thrust hurriedly forward towards Mons to shield the French left, found itself in presence of not less than four army corps with numerous cavalry constituting the swinging fist and sabre of the German encircling advance. By the evening of the 23rd ‘Plan XVII’ had failed in every single element. The French armies of the right were thrown back into France and were entirely occupied in defending themselves. Their armies of the centre and the left were in full retreat towards Paris and the south, and the British Army, isolated and beset by overwhelming numbers, was in the direst peril of complete destruction. So much for ‘Plan XVII.’
The utmost secrecy had naturally been maintained by the French about their general plan. The existence of their nation was at stake. Neither the British Cabinet nor what was left of the War Office were in a position to understand what was passing. I do not know how far Lord Kitchener was specially informed. I think it very improbable that he shared the secrets of the French Headquarters to the extent of being able to measure what was happening on the front as a whole. If he shared them, he did not show it by any remark which escaped him. He knew, of course, all there was to be known about the situation of our own army, and a good deal about the forces contiguous to it.
As the shock drew near, Prince Louis and I felt it our duty at the Admiralty to free Lord Kitchener’s hands in every respect and to bear to the full our burden of responsibility. I therefore wrote to him on the 22nd August as follows:
The Admiralty are confident of their ability to secure this country against invasion or any serious raid. If you wish to send the 6th Division abroad at once, we should not raise any objection from the naval standpoint. The situation, now that both the Navy and the Territorials are mobilised and organised, is entirely different from those which have been discussed in the Invasion Committee, of the C.I.D.[[43]]; and if you want to send the last Regular Division, the First Sea Lord and I are quite ready to agree, and so far as possible to accept responsibility.
He replied: