were unavoidable, but it was found far safer for infantry to run the risk of an occasional short burst than to let the barrage run away from them, leaving them exposed to enemy machine-guns.
Two other points in connexion with the Somme battle are especially worth noting. First, several attempts were made to operate on a really large scale by night, and on one occasion at least considerable success was won. Secondly, tanks made their first appearance, an event of real historic importance.
Nevertheless it must be admitted that 1916 brought the Allies little if any nearer to the longed-for " break-through " than had 1915, and largely for the same reasons. Again it was evident that prolonged bombardment was the enemy of surprise. Again it had been found that the first system of defence was far less difficult to deal with than were the less well-organized and comparatively ill-defined lines in rear. In addition it was dis- covered that the shell-torn ground opposed a formidable obstacle to the movements of the attacking infantry, while every hole was a ready-made emplacement for a German machine gun. 1 Great things had indeed been achieved both by the British and the French armies but the enemy was not crushed, and after months of fighting on an unprecedented scale he still preserved an unbroken front from the English Channel to the Swiss moun- tains. This time the explanation was held to be that, after all, the system of limited objectives was wrong, for the delay neces- sitated by the methodic preparation for each successive attack merely permitted the enemy to recover from the previous reverse, to bring up reserves of infantry and artillery, and to oiganize a fresh defence. Thus at each stage of the battle the defence grew stronger, and the attack weakened until it at last died from exhaustion. From this premise it followed that if real success was to be won the artillery preparation must be heavier than ever but in greater depth, and the infantry must pass through all the successive lines of defence in one irresistible rush. Such was the teaching of the French official instructions of Dec. 1916 which prepared the ground for Gen. Nivelle's dis- astrous attack in April 1917.
Lessons of 1917. Unlike its predecessors, the campaign of I9T7 was singularly unfruitful in tactical ideas. Partly owing to insufficient preparation, partly to over-confidence and partly to want of secrecy for it was commonly reported that every flower-seller in Paris knew exactly what was intended the great French offensive by the IV., V. and VI. Armies met with a severe reverse. The subsidiary attack by the British I., III. and V. Armies was more successful, but again resistance was found more difficult to overcome as the attack progressed, and the operations were finally abandoned when it became evident that the main attack, from which so much had been hoped and expected, could not attain its object. .
The principal scene of operations then became the Ypres area. First the capture of the Messines ridge, and then the prolonged attack, in appalling weather and on a narrow front, against the Passchendaele ridge. As had happened on every previous occasion, the first system of enemy defences fell easily enough, 2 but difficulties increased just when, theoretically, they should have been most easy to overcome. The artillery " preparation," on a scale far greater even than in the Arras battle of April, did its work only too well, for, coupled with the heavy rains, it converted a naturally swampy country into a pock-marked morass, intensifying in a high degree the troubles of the infantry, and greatly curtailing the usefulness of the tanks, which were by this time an important new arm of offense. During this period, too, the use of gas, especially the newly discovered " mustard " variety, became more persistent and more general than ever before. Masks were worn for hours on end, and so impregnated did the soil become that many men suffered merely
1 In addition the British armies in particular had to overcome almost incredible difficulties in keeping up the requisite supplies of ammunition and food over a country which was almost devoid of roads. It was indeed found necessary to institute a regular road department of the, transportation directorate.
' It should also be noted that the perfection (coupled with ample supply) of instantaneous fuze now made the destruction of wire defences a far simpler affair than it had been before.
from sitting or lying down to rest. Never has any army fought under greater disadvantages than did the British during the autumn of 1917, yet, even if it did not do what was hoped from it, it is only necessary to read Ludendorff's account to realize how heavy was the strain upon the German resources. Moreover, under the leadership of Hindenburg and Ludendorff , the defensive strategy and tactics of the German army had been radically overhauled during the winter of 1916-7, and the moral of the troops had been wonderfully improved. Indeed, the army which held the French on the Aisne, the British at Arras and the combined Allies round Ypres was altogether different in spirit from that which had been hunted back to the Hindenburg line during the previous winter. Even the air service responded to the new spirit, and the Entente troops no longer enjoyed the immunity from bomb attacks which had been theirs throughout ; 1916; far from it. Such was the effect of the masterful and trusted leadership which now had control of the German army.
Tactically, the principal change brought about by the new regime was a greater elasticity in defence, which aimed at affording as ill-defined a target as possible to the attacking artillery and the vaguest possible objective to the assaulting waves of infantry. In reserve were held certain battalions 1 whose duty it was to advance to the counter-attack as soon as- it was known that an attack had been launched, and thus it came about that more than once infantry which was in process of organization and consolidation after a successful attack found itself thrown upon the defensive and perhaps forced back from a position which had been dearly won. Special aeroplanes were detailed to look out for these counter-movements, and special batteries to deal with them, sometimes by putting down a defensive barrage of gas, and from these small beginnings grew up that war of movement which gradually reasserted itself and increased in intensity until at last the war was lost and won. More and more as the great attacks, whether French, British or combined, failed to win a decisive result, it was realized that in some way or another the element of surprise must be rein- troduced, for without it the offensive was deprived of almost half its power. But the question was, How could the enemy defences be overcome without the preliminary bombardment which inevitably " gave away " the assailant's intended plans? The solution of the problem was at last found in the use of tanks, and at the battle of Cambrai tanks came into their own. 3 Massed secretly by night conveniently near the objective, and advancing when the time came under cover of an artillery barrage, but over ground which had not been rendered impassable by tons of heavy shell, the tanks effected a complete surprise, passed line upon line of defences, and enabled supporting infantry to occupy an important area of ground with but little loss. So severe had been the drain upon the German reserves during the Ypres fighting that for some twenty-four hours the British troops were within an ace of really effecting a break-through, and Ludendorff has himself said that if they had been able to push on a little farther they might have broken in upon his communications and so have scored a considerable strategical success. But the drain upon the British reserves had been no less heavy than upon the German, and the necessary weight to turn a tactical victory into a strategical success was just lacking. In the end Ludendorff was able to mass troops for a counter-attack, and some of the ground which had been lost was re- won; but for the Allies by far the most important result of the Cambrai fighting was that the " trouistes " had been able to justify the faith which was in them and to show that there was a way leading to decisive victory namely the proper cooperation of infantry, tanks and guns. The seed sown at Cambrai bore rich fruit in the campaign of 1918, but before it could do so Ludendorff was to show that, even without tanks, a break-through was not impossible.
The " Break-through " in igiS. In discussing the first great French effort to break through the German defensive lines, that
- It should be noted that the earliest embryo of the tanks made its
appearance against Bullecourt in May 1917 ; but the number of these new engines was then insufficient and their tactics were not well understood. The attack failed, but the date is important historically.
