A defeat in these conditions would have cut off our armies from Paris and from the British forces and at the same time from the new army which had been constituted to the left of the English. We should thus be running the risk of losing by a single stroke the advantage of the assistance which Russia later on was to furnish.
General Joffre chose resolutely for the solution which disposed of these risks, that is to say, for postponing the offensive and the continuance of the retreat. In this way he remained on ground which he had chosen. He waited only until he could engage in better conditions.
The limit of the retreat.
In consequence, on September 1, he fixed as an extreme limit for the movement of retreat, which was still going on, the line of Bray-sur-Seine, Nogent-sur-Seine, Arcis-sur-Aube, Vitry-le-François, and the region to the north of Bar-le-Duc. This line might be reached if the troops were compelled to go back so far. They would attack before reaching it, as soon as there was a possibility of bringing about an offensive disposition, permitting the co-operation of the whole of our forces.
On September 5 it appeared that this desired situation existed.
The First German Army, carrying audacity to temerity, had continued its endeavor to envelop our left, had crossed the Grand Morin, and reached the region of Chauffry, to the north of Rebaix and of Esternay. It aimed then at cutting our armies off from Paris, in order to begin the investment of the capital.
The German lines.
The Second Army had its head on the line Champaubert, Etoges, Bergeres, and Vertus.
The Third and Fourth Armies reached to Chalons-sur-Marne and Bussy-le-Repos. The Fifth Army was advancing on one side and the other from the Argonne as far as Triacourt-les-Islettes and Juivecourt. The Sixth and Seventh Armies were attacking more to the east.
But—and here is a capital difference between the situation of September 5 and that of September 2—the envelopment of our left was no longer possible.