Battle of the Marne—End of German Retreat and the Intrenched Line on the Aisne River.
At every point but one the Germans had a right to deem the day successful. The only reversal had been a minor one before the forest of Crécy. Yet, of all the generals on that front Von Kluck alone was in a position to see the gravity of the situation. The British had caught him on the flank as he tried to pierce the left wing of General d'Espérey's army, and if he should now retreat, that army could envelop him and thus catch him between two fires.
Next morning, Monday, September 7, 1914, another glorious summer morning, saw a resumption of the battle along exactly the same lines, with the same persistent attack and defense along the eastern part of the front, and with the British making full use of the blunder made by the German right. General von Kluck had realized his plight, but, even so, he had not secured an understanding of the size of the force that was threatening his flank, and he sent as a reenforcement a single army corps which had been intrenched near Coulommiers on the Grand Morin. The British had three full army corps and were well supplied with cavalry and artillery. Yet Coulommiers was Von Kluck's headquarters and actually, when the Germans were driven back and the British troops entered the town, Prince Eitel, the second son of the kaiser; General von Kluck and his staff were compelled to run down to their motor cars and escape at top speed along the road to Rebais, leaving their half-eaten breakfast on the table, and their glasses of wine half emptied. One of the most dramatic cavalry actions of this period of the war took place shortly before noon, when one hundred and seventeen squadrons of cavalry were engaged. In this action the British were successful, but the German cavalry were tired and harassed, having been severely handled the day before.
In this engagement between the British and the German right, all the odds had been in favor of the British, and success meant merely the grasping at opportunities that presented themselves. Still, by constantly striking at General von Kluck's exposed flank, his frontal attack of General d'Espérey was so weakened, that, toward evening at the close of two days of continuous and very severe fighting, the Fifth French Army was able to advance and hold the position from La Ferté-Gaucher to Esternay. The ground gained was valuable but not essential, yet it made a profound impression.
General d'Espérey's step forward was the Germans' step back. It meant that the road to Paris was barred. How fully this was realized may be seen from an order signed by Lieutenant General Tuelff von Tschepe und Weidenbach and found in the house that had been occupied by the staff of the Eighth German Army Corps when the victorious French entered Vitry-le-François. The order was dated "September 7, 10:30 p. m." and it read as follows:
"The object of our long and arduous marches has been achieved. The principal French troops have been forced to accept battle, after having been continually forced back. The great decision is undoubtedly at hand. To-morrow, therefore, the whole strength of the German army, as well as all that of our Army Corps, are bound to be engaged all along the line from Paris to Verdun. To save the welfare and the honor of Germany I expect every officer and man, notwithstanding the hard and heroic fights of the last few days, to do his duty unswervingly and to the last breath. Everything depends on the result of to-morrow."
Much did, indeed, depend on the result of the morrow, and for the third day, again, it was General von Kluck's initial move that brought disaster to the German side.
Why was it that Von Kluck, instead of marching directly on Paris, as would have been expected, made a detour, having as his object not the capital but the French army? It may be said in favor of it that the decision taken by the German General Staff was in conformity with the military doctrine of Napoleon. According to this doctrine, a capital, whatever its importance, is never more than an accessory object, geographical or political. What is of importance is the strategical object. The strategical object is the essential, the geographical object is only accessory. Once the essential object is attained, the accessory object is acquired of itself. Once the French armies had been beaten, thrown back, and dispersed, Von Kluck could return to the capital and take it easily.