The effect was not moral merely, though _moral_ had not a little to do with it. The effect was in the main material. War wastage arising from fatigue and privation must have reduced the effective strength of the German armies in nearly as great a degree as losses in killed and wounded. If _on September 12_ we put the armies which turned to hold the new line from Compiègne to Verdun at 600,000 men still fit for duty, we shall be adopting probably an outside figure. Had this force, so reduced, not been able to make a stand along that new line, it must have been destroyed largely through exhaustion and famine. It was saved not, as imagined, chiefly by the defence works thrown up north of the Aisne and across the highlands to the Argonne. It was saved mainly by the tactics and by the energy of General von Kluck. Rightly described by the British Official Bureau, doubtless on the authority of Sir John French himself, as "bold and skilful," those tactics form one of the outstanding features of the campaign, and they ought justly to be considered among the greatest feats in modern war. They are on the same plane indeed as the strategy and tactics of General Joffre, and these, beyond doubt, rank in point of mastery with the campaign of Napoleon in 1814. In this very area of Champagne on the eve of his fall the military genius of Napoleon was, like lightning in the gloom of tempest, displayed in its greatest splendour. For a thousand years this region of plateaux and rivers has been the arena of events which have shaped the history of Europe.[16] The features it offers for military defence are remarkable. Versed in the campaigns of Napoleon, aware of what have proved to be his mistakes, knowing the country in its every detail, knowing and judging rightly the qualities and capabilities of his troops, General Joffre drew the Germans on step by step to overthrow. The great feature of his plans was that this was meant to be an overthrow which would govern the fortune of the war. In great fact that aim was achieved, but in part also its fulfilment was postponed. On the retreat of the German armies from the Marne there were, in order to bring about the destruction of those armies as a fighting force, three things which the Allies had to accomplish, and accomplish, if possible, concurrently. The first was to cut the German communications with Luxemburg and Metz by barring the roads and railways across the eastern frontier; the second was to push forward and seize Rheims, and the outlet through the hills north of the Aisne at Berry-au-Bac; the third was to force the troops of von Kluck eastward off their lines of communication along the valley of the Oise, and to do that, if it could be done, south of the Aisne. All three objectives were of great consequence. The third, however, was the most important of the three.