Nevertheless the Russian revolution had one beneficial effect upon the Balkan situation. It removed one of the two influences which had protected Constantine and enabled him to counterwork Entente policy and strategy in the Near East. The other was neutralized by connivance in Italy's proclamation of a protectorate over Albania on 3 June; and with this compensation she was induced to remove her ban on Venizelos and to risk that greater Greece, which with a free hand that statesman bade fair to achieve. France was whole-hearted in supporting him. The chief islands had one by one rallied to his cause in the spring, and by the end of May he had 60,000 troops at his disposal. On 11 June M. Jonnart arrived at Athens as plenipotentiary for the Entente to insist on Constantine's abdication. Troops were moved down into Thessaly; the Isthmus of Corinth was seized, and warships anchored off the Piraeus. Constantine had no choice, and under compulsion nominated his second son Alexander as his successor. On the 13th he left Athens for Lugano, and on the 21st Venizelos arrived from Salonika and formed a government. The German agents were expelled, and the Greek people were reconciled to the violence of the proceedings by the substantial consolation of the raising of the blockade. Less happy was the effect of the Russian revolution in Asia Minor. All idea of an advance from Trebizond and Erzingian came to an end, and the projected campaign which was to have given the Russians Mosul while Maude advanced to Baghdad was abandoned. On 30 April the Turks announced that the enemy had evacuated Mush. In May they left the Dialah, and in July retreated from Khanikin into Persia, leaving the British right wing in the air. Gradually they abandoned Persia to the principle of self-determination and to the Turks, and Armenia to fresh experiments in massacre. Even on the Salonika front Sarrail suffered from the retiring habits of his Russian troops, and at Gaza Murray felt the force of Turkish divisions released from Russian fronts. There were at least six divisions to oppose him when he renewed his attack after three weeks' interval on 17th April. His communications had been greatly improved and the railway brought up to Deir-el-Belah, but so too had the Turkish defences, and there was little to say for a frontal attack by inferior forces without the chance of surprise. The political demand for an Egyptian contribution to the combined Allied offensive seems, however, to have been inexorable, and Sir Charles Dobell was committed to an enterprise not unlike our attacks in Gallipoli. Some initial success was won on the 17th, and the ground gained was prepared on the 18th for a final effort on the following day. Samson Ridge near the coast was taken, but Ali Muntar defied all our efforts, and counter-attacks deprived us of much of the ground that was won. Seven thousand men had been lost, and Turkish reinforcements were still arriving. Gaza could not be taken by frontal attack without greatly superior forces; and the British had to look for success to another general and a different strategy, and to postpone from Easter to Christmas their Christian celebrations in Jerusalem. The brightness of dawn in the East was clouded, and the flowers of hope that bloomed in the spring drooped in the Syrian summer and in the furnace of war in the West.
CHAPTER XVI
THE BALANCE OF POWER
THE breakdown of the strategical offensive of the Entente in the spring of 1917 was almost complete. Russia had gone her own way to military insignificance, France had failed in her far-reaching design of crushing the German front on the Aisne, Haig's victory at the battle of Arras secured merely a tactical advantage, the offensive from Salonika never started, and that from Egypt was held up at the gates of Palestine. In the absence of a combined General Staff for the Entente, it required months of individual thought and interchange of views to elaborate any alternative scheme and to readjust national forces for its execution; and the campaigning season would assuredly close before effect could be given to a fresh plan of campaign. The new Governments in England and France showed no greater foresight than the old, and had made no further progress towards a single strategical mind. Indeed, for the rest of 1917 divergence seemed to grow, and there was no such combined operation as the Somme campaign of 1916. Activity travelled away from the point of liaison, and each ally concentrated its attention more and more on its own particular front. Italy as usual had eyes only for Trieste and Albania, France turned from the Somme and the Oise to the Aisne and Verdun, and England's effort came north towards the Belgian coast. This divergence resulted from the changed view of the military situation imposed upon the Entente by Nivelle's failure. He had believed that the time had come for ambitious objectives; Haig had demurred and clung to the idea of operations limited in their scope like that of the Somme; and Ptain accepted that view when he succeeded Nivelle. There might, of course, have been limited offensives on the upper Somme and the Oise where the two armies joined; but it was here that the Siegfried line most firmly barred the way, and when towards the end of the year a new tactic had been evolved to surmount that barrier, it was applied prematurely and without French co-operation. The unity of the Entente did not extend to community of ideas or simultaneous experiment; and novelties which might have been overwhelming if tried in unison all along the line only achieved a partial success when adopted by one of the Allies on a limited front.
Given, however, the impossibility of another combined strategical plan for 1917, there were urgent motives and sound reasons for the extension of Haig's offensive northwards from Arras to the coast. If it were successful beyond expectation, it would achieve all that Nivelle had hoped to do by a frontal attack, and would compel a general German retreat by turning the enemy's flank as Joffre had tried to turn it in October 1914. But short of such extravagant anticipations it might materially help to win the war by defeating the real German offensive for 1917. That was not a campaign on land at all, but on sea by means of the submarine, and the chief basis of operations was the Belgian coast. Submarines emerged from other lairs, but the German command of the Belgian coast shortened their distance from their objectives by hundreds of miles and correspondingly lengthened their range of operations. Bruges was their headquarters; situated inland, but connected by canal with Zeebrugge and Ostend, it afforded a base immune from any attack save those of aircraft, and Bruges was the real objective of our Flanders campaign. Incidentally, too, the Belgian coast provided harbours whence light German surface craft made occasional raids on British coasts, commerce, and communications, and also for those aeroplane attacks which became a serious nuisance as the year wore on. Apart from these considerations the German hold on Flanders was the bastion of their whole position west of the Meuse; and, but for the natural feelings of Paris, a more strenuous attempt might well have been made earlier in the war to deprive the enemy of its advantages. Obviously in the summer of 1917, if the two Allies were to be left to their own devices, there was none which suited us better than the Flanders campaign, and the official American commentator opined that it held out more fruitful prospects than the battle of the Somme. The drawback was that campaigning in Flanders depended upon the weather: a rainy season turned its flats into seas of mud, and the third quarter of 1917 was one of the wettest on record.
A preliminary obstacle to be overcome was the Messines-Wytschaete Ridge which dominated Ypres and the whole of the line from which an offensive in Flanders could start. Preparations to deal with it had been in progress since early in the year, and heavy guns had also been mounted on our positions near Nieuport. The plan indeed had been in Haig's mind since November 1916, and even earlier than that Sir Herbert Plumer had been training the Second Army for its task; it had had no serious fighting since the second battle of Ypres in April 1916, the battle of the Somme having been fought by the Fourth and Fifth, and that of Arras by the First and Third. The victory, however, was to be largely a triumph of engineering science. For nearly a year and a half tunnelling had been in progress under the ridge, and at dawn on 7 June nineteen huge mines were exploded beneath the enemy's lines in the greatest artificial eruption that had ever shattered the earth's crust. Ten days' surface bombardment had already obliterated much of the German defences, and it says something for the German moral that any resistance was offered at all when our troops advanced over the ruins of the soil. Messines was cleared by New Zealanders by 7 a.m., Wytschaete fell by noon before Ulstermen and Irish Nationalists fighting side by side, and Welshmen captured Oosttaverne a few hours later. The battle could not have have been better staged to exhibit the co-operation of the British Empire and of mechanical science and human valour. A few days later Australians pushed on to Gapaard and La Potterie in the direction of Warneton, and the Germans withdrew from all their positions in the salient. The danger to Ypres which had threatened for over two years and a half and had cost so much in British blood, had at last been exorcised, and from being an almost forlorn hope of defence the Ypres salient became the base of a promising advance (see Map, p. 288).