More than two years before the war concluded a junior officer from the front remarked that he could not say when, but knew where, it would end, and that was not far from our existing lines in France and Flanders. As time wore on and the limitations of strategy under modern conditions grew clearer, the war assumed more and more the aspect of a single battle varying in its intensity from season to season and place to place, but constant in its continuity and in its absorption of the principal forces of the main belligerents. The unity of control culminating in unity of command which marked the closing stages of the war was therefore not so much a brilliant improvisation on the part of any general or statesman as the inevitable result of the history of the war; and the misfortunes of the Entente did more than its foresight to bring that consummation to pass. In the main it was due to the gradual weakening and then the collapse of Russia, which first involved the ruin of Serbia and Rumania and the wrecking of our Balkan plans, and finally dissolved the Eastern front. There could have been no unity of command had Russia remained our predominant military partner; and even in the West it never comprised the Italian Army, which retained its independence of action or inaction until the end of the war. But in 1918 the Italian front sank into a subordination almost as marked as the Russian, and the war that counted grew to a climax where it had started between the Alps and the Belgian coast. There were concentrated the French and British armies which Germany must beat before she could win peace; and there came in the American hosts which turned the scale against her.

With or without unity of command, the two million American troops which ultimately crossed the Atlantic would have given us the victory; and the view that the war was won by unity of command is as superficial as the view that the battle of St. Quentin was lost by the lack of it. That battle was lost because the Versailles Council, acting on the advice of its French rather than its British members, misjudged the direction of the coming German offensive and misplaced the reserves at its disposal. Unless, which may be the case, Foch was at variance with his French colleagues on this point, his appointment as generalissimo at any earlier stage would not have affected the results of these mistakes. Unity of command might, indeed, have led to an even more extensive weakening of the threatened British front in order to make absolutely secure that French front which the French were convinced was the German objective, and a demand was made for a further British extension beyond Barisis, but was successfully resisted at the Versailles Council before the unity of command had been established. That does not absolve the British Cabinet from its complicity in the blunder. It was equally responsible to the British people for British lives whether it was acting on its own initiative or on the mistaken advice of an ally; and there were also sins of omission of its own. Not only had it been advised by Sir Henry Wilson that the German offensive would come on the British front, but it had been warned that if it came where it was anticipated, that front, thin as it was, could not be expected to hold unless reinforcements, for which repeated requests were made, were dispatched. Remonstrances fell on deaf ears, although there were nearly 300,000 troops available in England. Mr. Lloyd George afterwards called them first-class troops, and congratulated himself and the country on the fact that they were transported to France within a fortnight after the damage had been done. For this, the most culpable Cabinet failure in the war, others besides the Cabinet were to blame; and it must be ascribed ultimately to the national sins of intellectual sloth and ignorance. Those hundreds of thousands of troops, shown to be superfluous in England by their subsequent dispatch to France, were kept at home because persons in authority believed they were needed to do the work of the British Navy and defend our shores against a German invasion. Throughout the war loquacious generals, who were not employed at the front, harped at home on that alarm, supremely ignorant of and indifferent to the unbroken experience of the world and the teaching of naval history, that military invasion across an uncommanded sea is an utter impossibility. But there was no one to teach the War Cabinet this elementary truth, and least of all could it be taught by the eminent lawyer and the able railway director whom Mr. Lloyd George successively appointed to the Admiralty to represent the ripest naval wisdom of mankind. It remained for the nation to pay the cost.

The great attack was launched at dawn on Thursday, 21 March, precisely against that sector of the British front indicated by Sir Henry Wilson two months before; and Gough's Fifth Army, which held it lightly with fourteen divisions against forty, was doomed to defeat by the failure of both the British and the French Governments to provide adequate reserves which existed in abundance both in England and in the rear of the French line, and by the fact that Haig was more anxious about his shallow front in Flanders and Ptain about his in Champagne than either was about the Somme. Generally speaking, the British front grew thinner from north to south until between the Somme and the Oise Gough had less than a bayonet a yard; and Ludendorff knew it. He also made skilful use of the advantage which the possession of the interior lines gave him in the St. Quentin-St. Gobain salient. He could mass his troops in that angle without revealing which side he meant to attack, and thus neutralize that observation which superiority in aircraft gave his antagonists. It was not so much that he brought up his forces at night and concealed them in woods, which are leafless in March, as that the bodily eye of the airmen failed to discern his intentions. He had other incidental advantages: that laborious spade-work which characterized the German Army was not a distinguishing feature of either the British or the French; and both the trenches we took over south of St. Quentin and our own to the north of it left a good deal to be desired in their defensive strength, while the great bridgehead under construction to protect the Somme south of Pronne had not been completed. The Allied advance had been slow, but since 1916 a confident conviction possessed the Allied armies that they would only move in a forward direction. Ludendorff was also able to withdraw his six divisions and many Austrian batteries from the Italian front, assured that no Italian offensive need be feared; and his tactics came as a surprise in spite of the practical warnings given at Caporetto and Cambrai. They were based not so much upon superiority of numbers as upon superiority of the selected troops to the average of the forces opposed; and success depended less upon the weight than upon the sharpness of the weapon used for the blow. Hindenburg liked a hammer; Ludendorff chose an axe with which to cleave the enemy front. When it was cleft, inferior metal might be used to widen the gap between the French and British armies and drive the latter to the coast while the former was being crushed.

The German offensive was facilitated by the abnormally dry season, which reduced the strength of the water-defences of the British right, and a dense fog favoured the attack on our forward positions. The Germans got their infantry across the Oise canal north of La Fre without being noticed, and many of our outposts were surrounded before it was known that the attack had begun, although a brief bombardment by gas and other shells had drenched our line and areas miles behind it all along the front (see Map, p. 338). The forward zone resisted heroically, but by noon the Germans were through it west of La Fre and were in our battle-zone north of St. Quentin at Ronssoy. Between these two extremes of Gough's front they reached in the afternoon Maissemy, north of St. Quentin, and the line Essigny-Benay south of it. Farther north less progress had been made against Byng's Third Army, but the Germans had reached St. Leger in their effort to thrust a wedge between Arras and Cambrai, and many villages had been captured. The prospect was gloomy for the morrow, since, although the Germans had already used sixty-four divisions they were prepared to throw in fresh ones each succeeding day, and it would be several days before reinforcements could reach the Somme either from our reserves in Flanders or the French reserves in Champagne.

The Germans made comparatively little headway on the 22nd against the Third Army; but Gough's last reserves were thrown in without stopping the German advance on our right, and the meagre French division which Fayolle was able to send across the Oise could not dam the torrent. At night the enemy had penetrated our third defensive position, and Gough ordered a retreat to the unfinished bridgehead on the Somme. Byng's right had to conform to this movement, which did not stop east of the Somme; for on the 23rd the Germans had crossed the river south-east of Ham, more than a dozen miles from their starting-point, and the Pronne bridgehead had to be abandoned. Even on the west bank Gough's right was thus endangered, and his left was threatened by a German attempt to break a gap north of Pronne between his army and Byng's Third. This effort on the Somme, where it runs due west from Pronne to Amiens, now became the chief and most promising objective of the German strategy. The link between our two armies was extremely fragile, and misunderstandings arose between the two staffs. Fortunately the worst disaster was averted by Byng's timely withdrawal from Monchy, which disconcerted and postponed the German attack on Arras.

On Sunday the 24th the task of the British was threefold--to stem with French assistance the German advance on our right between the Somme and the Oise, to hold the line of the river from Ham northwards to Pronne, and to repel the German thrust between the Third and Fifth Armies north of the river bend. They were partially successful in the first two tasks, but north of the Somme the Germans got into Combles and the Third Army had to make a big retreat, surrendering Bapaume and nearly all the painful gains of the 1916 Somme campaign. The Germans renewed the attack with great energy on the 25th, and the British were unable to hold them up on their improvised lines. Before night they were ordered to take their stand on the old Ancre defences. This movement exposed the left flank of Gough's forces on the Somme; his front had also been driven in by German attacks across the river, while his right had been forced back beyond Guiscard, Noyon, and Nesle. Fissures began to appear on the broken front; there was something very like a gap between the French and British near Roye, and another between Byng's Fourth and Fifth Corps across the Ancre, besides that between his and Gough's armies. Byng was the first to re-establish his line, partly because reinforcements from the north reached him first. Early on the 26th the Germans had broken through our old line between Beaumont-Hamel and Hbuterne and taken Colincamps, where they had not been since 1914; but in the afternoon they were driven out again, and the recovery was permanent. Here at least the German advance had reached its limit, and there was some significance in the fact that here on that afternoon the British whippet Tanks first appeared in battle.

Gough was not so happy. He had begun to collect a miscellaneous force, like that which stopped the final German thrust at Ypres on 31 October 1914, consisting of all sorts of combatant and non-combatant details, to check the German rush on the Somme; but threats on his left, right, and front compelled him to retreat to a line running south from Bray and behind that held by the French before the battle of the Somme. Still the Germans advanced towards Montdidier, seeking to break through between Gough's right and the French, who had been driven off south-west of Roye. But the worst of the danger was north on the Somme, where Byng's orders were misunderstood and his extreme right, instead of holding the line Albert-Bray to protect Gough's left, fell back five miles to Sailly-le-Sec. The result was that on the 27th the Germans were able to cross the Somme behind Gough's left at Chipilly and compel his retreat to a line running from Bouzencourt S.E. to Rosires. There Gough's centre stoutly maintained itself during the day; but to the south the Germans drove the French out of Lassigny and Montdidier and seemed in a fair way to break the liaison between the Allies, while north of the Somme the Germans had got into Albert and Aveluy wood.

Nevertheless the clouds were beginning to lighten. The violence of the German attack was exhausting to the attackers; their communications now lay across the devastated area, and rain soon came to clog their movements. Their front of attack was, moreover, being steadily narrowed from fifty to twenty miles. The French had forced the Germans to leave the Oise after Noyon, and while their advance continued it did so with a lengthening flank no longer protected by the river. Unless Von Hutier to the south or Von Buelow to the north could break these containing and solidifying barriers, the front of the German attack would be reduced to a hopeless point before it got to Amiens. The attempt was naturally made against Arras by Von Buelow's comparatively unwearied army, and on the 28th he resumed his frustrated attack of the 23rd. This time the Germans had no fog to help them, and their troops assembling for the attack were decimated by our artillery. Nowhere did they succeed in piercing the battle zone, and a second attack in the afternoon fared no better. This was the decisive failure of the German offensive, and north of the Somme our front was now secure. South of it the Germans made some further progress on that day. The Rosires salient had to be abandoned to the Germans pushing south of it across the Somme, and a retreat made to the angle of the Luce and Avre rivers. Fayolle also was driven back to the Avre, but by counter-attacks north and south of Montdidier he prevented the enemy from debouching from that city.

The situation continued grave and the fighting severe for the next few days, but retreat and pursuit had merged into a battle on a line with take as well as give. The French front was extended up to the Luce and an extemporized Fourth Army replaced the weary remnants of the Fifth. More important was the appointment of Foch as commander-in-chief on the 25th after a conference at Doullens between Haig and Ptain, Lord Milner and Clmenceau, though it cannot have had much effect upon the operations which checked the German advance by the end of March. On 4 April Von Hutier made a final attempt to reach Amiens, and drove the Allies out of the angle of the Luce and Avre and from the west bank of the latter back to a line running west of Castel, Mailly-Raineval, Sauvillers, Cantigny, and Mesnil St. Georges. But farther the Germans could not advance either north or south of the Somme, though away to the east the French had to evacuate the sharp salient between the Oise from La Fre to Chauny and the St. Gobain forest, and to fall back behind the Aillette. The first act in the great German offensive had failed in its strategical object of breaking the Allied line, but it had achieved incomparably more than any Allied offensive in the war; and the only advances to compare with it were the German invasion of France and Belgium in 1914 and of Russia in 1915. The Germans claimed by 4 April 90,000 prisoners and 1300 guns, and the Fifth Army had been practically destroyed. It was the most formidable offensive in the history of the world, and four times as many divisions were launched against the British in March 1918 as against the French at Verdun in 1916.

But it did not exhaust the German effort. There were other acts to follow, and the second opened on 9 April, immediately after the curtain had been rung down on the first. No second offensive could, however, approach in magnitude the original plan. The Germans excelled in forethought and in methodical preparation for which ample time was needed. They had had it in the winter, and had staked their hopes upon the success of their throw in March. Now they had to improvise, and their second thoughts were second best. There were, indeed, signs of indecision in Ludendorff's later moves. Possibly he regarded the Flanders offensive in April and the attack on the Chemin des Dames in May as diversions merely intended to draw reserves away from the Amiens front and facilitate a resumption of his original design with better chance of success. Certainly those offensives were begun with limited forces, and probably succeeded beyond his expectations. But the attack on the Amiens front was never seriously resumed in spite of the success of Ludendorff's diversions; and the remainder of the campaign, so far as German initiative was concerned, resolved itself after April into an effort to repeat with more success against the French Army offensives which had failed to dispose of the British. There can hardly have been much hope in Ludendorff's mind of decisive victory in a strategy which after April left the British front almost immune from attack, while American reinforcements were pouring in at the rate of hundreds of thousands a month. But the responsibility of continuing the war under such conditions and deluding the German people with false confidence was so serious that no admission is likely to be forthcoming yet awhile of the real intentions and thoughts of the German General Staff during the summer of 1918. The truth no doubt is that Ludendorff had only a choice between a confession of failure which was bound to ruin the Government and the class he represented, and a desperate effort to make what he could out of the military situation; and he preferred gambling, so long as he had anything with which to play, to an immediate confession of bankruptcy.