The attack on the German flank on the morning of 18th July had put an end to the enemy’s hope of an advance on Paris, and had forced him to assume the defensive. But in this he still persevered. His plan now was to defend the line of the Aisne, in the hope that the French would break their teeth on it, and that the battle would then decline into a fruitless struggle for a few miles of trench, like the other actions of the long siege warfare. He hoped in vain. Foch had no mind to waste a single hour in operations which were not vital. As early as 23rd July the Allies’ great scheme for the autumn battles was framed, and on Thursday, 8th August, Sir Douglas Haig opened the attack. Foch’s plan was to give the enemy no rest. He was like a swordsman who avoids his antagonist’s sledge-hammer blows, who with lithe blade pinks him again and again and draws much blood, who baffles and confuses him, till the crushing weight of his opponent has been worn down by his own trained and elastic strength. It was his business to wear down the enemy continuously and methodically by a series of attacks on limited fronts, aiming at strictly limited objectives, and to keep him ceaselessly harassed over the whole battle-ground. The campaign had developed like a masterly game of chess. From 21st March to 18th July Foch had stood patiently on the defensive. From 18th July to 8th August he had won back his freedom of action, cleared his main communications, and hopelessly dislocated the German plan. From 8th August to 26th September it was his task to crumble the enemy’s front, destroy the last remnant of his reserves, force him beyond all his prepared defences, and make ready for the final battle which would give victory. On 8th August Haig’s striking force was the British Fourth Army, under Sir Henry Rawlinson, and part of the French First Army, under General Debeney. The front of attack was east of Amiens, astride the valleys of the Avre, the Luce, and the Somme. Haig’s immediate aim was to free his communications—that is, to push the enemy out of range of the main railways behind his front—as the French had done on the Marne, and to this end the enemy must be driven out of range of Amiens.