'Pas de victoire sans bataille.' The French Generals in 1870 had forgotten this elementary truth. They prepared their battles as though they were reviews; with them it was not a question of an enemy to be struck or of the blows to be dealt or of the hammer which was to strike the blows; they had forgotten that war is the employment of Force. Everything, then, with Marshal Foch, leads up to the supreme blow, delivered not all along the line but against one point in it; in Napoleon's words, it is sufficient, in order to be victorious, that one should be the stronger at a given point at a given moment. How Marshal Foch, along with the other Commanders, must have puzzled over the riddle set by the trench-barrier in the west! Napoleon had declared that the whole art of war consisted in having more force than the enemy, even though one's gross numbers were weaker than his, at the point where one attacked or was attacked. But this development of static warfare, which even the acutest minds on the French General Staff had not foreseen,* seemed to make impracticable the application of Napoleonic methods, since no superiority of force at the chosen point, under the tactical conditions of 1915-17, had proved sufficient, except for a moment, to restore the war of movement and the possibility of the decisive battle. With what joy, therefore, must Foch have realised after the Austrian victory at Caporetto in October, 1917, and still more after the British break-through at Cambrai in the following month, that the strategic surprise, the sudden and unexpected blow, by which Napoleon had gained his greatest victories, could still be achieved. To break the will of the enemy-such is the first principle that the study of war indicates to us; to break it by an unexpected blow of supreme vigour is the first consequence that this principle brings with it.' So much for theory; but it was not until July 18 that Marshal Foch could translate theory into practice. Then the Napoleonic method had its chance.

General Canonge makes an exception in favour of a Lieut-Colonel Mayer, who, he says, in 1902 predicted the prolonged extension of the battle-front, and foresaw la ligne s' arrêtant à un point d'appui, à une mer, à une montagne, à la frontière d'une nation neutre.'

First comes the period of preparation. The battle has to be worked for; ground which is favourable to the enemy as a jumping-off point has to be taken from him; ground useful for the intended attack has to be seized and held. The troops engaged on the task of preparation must attack important points, seize them, install themselves there; defend them if they are attacked; retake them if they are lost; make of them a new base for new progress if the enemy does not attack them.' But except where the decisive attack is to be launched, all operations are to be carried out with the minimum of forces necessary. This is the doctrine of Economy of Force everything that can be spared must be saved and drawn off for the supreme, unexpected blow. But in the delivery of the final stroke there is no holding back, no husbanding of strength. Everything is thrown into the scales. The reserves are employed which have been

prepared, organised, held back, carefully nursed in order to execute the only act of the battle from which a result is expected the decisive attack; the reserves which have been husbanded with the most rigid economy, in order that the instrument may be as strong and the blow as violent as possible; released at last, without any secret thought of economy, with the settled idea of carrying in high combat a point chosen and determined; released, therefore, in mass, in an action surpassing in violence and energy all the combats of the battle, with the characteristics of surprise-mass and speed.'

It is an illuminating exercise to compare these principles with Marshal Foch's tactics from the close of the German offensive against Compiègne on June 15 to the opening of the counter-movement between Soissons and Château Thierry on July 18. There was first a period of preparation during which the French were continually active on the German flank against which the blow was being prepared. The chief seat of preparation was the forest of Villers-Cotterets, on whose outskirts the Germans lay; and the French made constant and successful efforts to the north and to the east of the forest to push the Germans back and to put an interval of a few miles between the observation-posts of the enemy and their own preparations. A German newspaper afterwards

declared bitterly that, while Ludendorff was sending expeditions all over Europe-to Finland, to the Caucasus, to the Ukraine and elsewhere-Foch was preparing his counter-stroke in the woods of Villers-Cotterets and Compiègne. But the Germans had failed at the time to take to heart the work of preparation that was going on under their eyes, for the simple reason that they had made up their minds that they could ignore the intentions of the French, like those of the Allies in general, and that they need not take the ordinary precautions which their military situation in fact demanded of them.

This same period illustrates also the doctrine of Economy of Force. We shall not yet know for some time the strength of the forces with which Marshal Foch during the three days July 15, 16, and 17, checked and arrested the offensive which the Germans launched from Château Thierry past Rheims almost to the Argonne. But it is known that his strength was much inferior to the fifty divisions which the Germans had assigned for the offensive; and that in Eastern Champagne, where the fate of the German attack was really decided, the wonderful victory of General Gouraud was due not to strength in men but to the bold and logical application of the 'zone' system of defence. Marshal Foch kept his reserves on the Soissons flank in readiness for the moment when the German offensive should be finally arrested. When, on July 17, he judged that the moment had come, he threw in all that he had. There is high British military authority for the statement that on July 18-the turning-point of the campaign-Marshal Foch threw into the battle virtually all his available reserves. Practice kept pace with theory.

There remains a point in Marshal Foch's theory and practice of war which has received little attention, but which is fundamental to the understanding of his method and furnishes one of the keys to the secret alike of his success and of the German defeat. It is his doctrine of sûreté, to which all through his lectures he returns as one of the prime conditions of victory. Sûreté involves all the measures which enable one to act, to strike, to deal the supreme blow and to exploit its success in security; it provides the liberty of action which alone

enables the chief to execute his plans. It must be achieved with due regard to economy of force, so that the utmost strength may be thrown into the blow which is expected to produce the decisive result; but at any cost it must be achieved, because without it there can be no secure foundation for the great attack. It follows that one of the main instruments in the policy of sûreté must be an efficient system of intelligence on which a general can base his plans, and distribute his forces economically, from day to day and almost from hour to hour; and Foch (following Napoleon) reserves some of his strongest censures for the generals who, from whatever causes, direct their actions by any other standard than a constant flow of information about the enemy, his strength and his intentions.

No general can avoid being sometimes misled or can always have a complete and accurate service of information. Napoleon himself was often in ignorance of his enemy's designs and dispositions; and the unexpected German break-through on the Aisne on May 27, 1918, shows how far was Foch himself from being always well served by his intelligence departments. But no excuse is admitted for the general who does not strain every nerve to inform and guard himself before he strikes. The Austrian tacticians,' said Napoleon, 'based their plans on uncertain reports which, even had they been accurate at the moment when the plans were settled, ceased to be accurate on the next day or the day after that, that is to say at the time when the plans were due to be executed.' Hence the necessity, according to the Emperor, of engaging in an action or drawing up a plan on no other basis than that of reports which are certain and accurate at that moment; from which derives the necessity, again, of organising a service of information which is capable of furnishing such reports.

After all, it may be said, this is an elementary requirement in warfare. True, but how far short of its fulfilment do most generals fall; and how different, had it been fulfilled, would have been the history of the German offensives of March 21, April 9 and May 27! The charge brought by Napoleon against the Austrians is brought by Foch against some of the French generals in the Franco-Prussian War. He says of them:

'There is no regularly organised service of information. On the contrary, it is rumours, whether well-founded or not, and generally magnified by fear, that will dictate military decisions; and how should these correspond to the reality of things? False theories, absence of the military spirit, of intellectual and intelligent discipline, complete ignorance of the sûreté in which these military victories have their embodiment, and of the liberty of action that sûreté alone can give -such were the causes of disaster.

'Ignorance of sûreté! In reality nothing prevented them from carrying out the simple orders that they had received; "Direct your march on Froeschwiller with all your forces." Not distance. . . not the enemy; the 5th corps had found no trace of the enemy on their march, but everything happened as though the enemy had been everywhere. They ought to have marched in spite of the enemy; they did not march even when he was not there. They regulated their conduct by false information which they did not verify; they failed to clear up the position; they failed to cover themselves against attack.'

Two further quotations, drawn from different lectures, will confirm the view that this doctrine of sûreté is not merely an important part of Foch's plan of war; it lies at its very heart. The first is from the lecture on 'Intellectual Discipline,' the second from that on 'The Strategical Surprise.'

'At the same time as we are preparing and combining an action against the enemy, our constant preoccupation must be to withdraw ourselves from the exercise of his will, to thwart the enterprises by which he might prevent our action from succeeding. Every military idea, therefore, every project, every plan must be accompanied by thoughts of sûreté.

'The conception of sûreté, which we have seen reigning as a sovereign mistress in the realm of tactics, and dominating beyond dispute the conduct of the troops . . . this conception reappears in the first rank among the considerations on which strategic dispositions must be based. Where there is no strategic sûreté, therefore, there is strategic surprise-that is to say, the possibility for the enemy of attacking us when we are not in a condition to give him a good reception, the possibility for him of impeding our concentration which has been insufficiently protected, while on our side our forces are engaged and led astray and compromised in wrong directions