Before we state it, and trace its later modification, it will be well to recall the main features of the problem to be solved.
The first fact which had to be reckoned with was that the main weight of the enemy was bearing down across the north and north-east, and was, for the moment, irresistible. Retreat, at the outset, was not, then, within the plan, but a condition of it. There was no choice; contact with the invader must be broken if any liberty of action was to be won back. Defeat and confusion had been suffered at so many points, the force of the German offensive was so markedly superior, that an unprepared arrest on the Belgian frontier would have risked the armies being divided, enveloped, and destroyed piecemeal.
If the first stage of the retreat was enforced, its extension was in some measure willed and constantly controlled. For all the decisions taken, Joffre must have the chief credit, as he had the whole responsibility. The abandonment of large tracts of national territory to a ruthless enemy cannot be an easy choice, especially when the inhabitants are unwarned, and the mind of the nation is wholly unprepared (the defeats on the Sambre and the Meuse were not known for several days to the civil public, and then only very vaguely). A less cool mind might have fallen into temporising expedients. Maubeuge was to hold out for a fortnight more; the 4th Army had checked the enemy, and Ruffey had repulsed several attacks; Longwy had not yet capitulated. But the Commander-in-Chief was not deceived. He had no sooner learned the weight of Kluck’s flying wing than he realised that the only hope now lay in a rapid retirement. The fact that the British force, holding the west flank, depended upon coast communications for its munitions, supplies, and reinforcements, was an element to be counted. In every respect, unreadiness in the north dominated the situation.
Evidently the retreat must be stayed, and the reaction begun, at the earliest possible moment. Not only were large communities and territories being abandoned: the chief German line of attack seemed to be aimed direct at the capital, which was in a peculiar degree the centre of the national life. This consideration, which no Commander-in-Chief could have forgotten, was emphasised in a letter addressed at 5 a.m. on August 25 by the Minister of War, M. Messimy, to General Joffre. It contained a specific order from the Government——probably the only ministerial interference with the operations in this period——thus phrased: “If victory does not crown a success of our armies, and if the armies are compelled to retreat, an army of at least three active corps must be directed to the entrenched camp of Paris to assure its protection.” In an accompanying letter, the Minister added: “It goes without saying that the line of retreat should be quite other, and should cover the centre and the south of France. We are resolved to struggle to the last and without mercy.”[31] No doubt, these measures would, to Joffre, seem to “go without saying.” The retreat, so long as necessary, must be directed toward the centre of the country, and at the same time the capital must be protected.