Faced with such a mental and physical blank wall, the logical military course was to go round it—by a wide manoeuvre through Belgium. Graf von Schlieffen, chief of the German general staff from 1891 to 1906 conceived and developed from 1895 onwards the plan, by which the French armies were to be enveloped and a rapid decision gained, and as finally formulated it came into force in 1905. To attain its object Schlieffen's plan concentrated the mass of the German forces on the right wing for this gigantic wheel and designedly took risks by reducing the left wing, facing the French frontier, to the slenderest possible size. The swinging mass, pivoting on the fortified area Metz-Thionville, was to con sist of 53 divisions, backed up as rapidly as possible by Landwehr and Ersatz formations, while the secondary army on the left wing comprised only nine divisions. Its very weakness promised to aid the main blow in a further way, for if a French offensive pressed them back towards the Rhine, the attack through Belgium on the French flank would be all the more difficult to parry. It would be like a revolving-door—if a man pressed heavily on one side the other side would swing round and strike him in the back. The German enveloping mass was to sweep round through Belgium and northern France and, continuing to traverse a vast arc, would wheel gradually east. With its extreme right passing south of Paris and crossing the Seine near Rouen it would then press the French back towards the Moselle, where they would be hammered in rear on the anvil formed by the Lorraine fortresses and the Swiss frontier.
Schlieffen's plan allowed ten divisions to hold the Russians in check while the French were being crushed. It is a testimony to the vision of this remarkable man that he counted on the inter vention of Britain, and allowed for an expeditionary force of oo,000 "operating in conjunction with the French." To him also was due the scheme for using the Landwehr and Ersatz troops in active operations and fusing the resources of the nation into the army. His dying words are reported to have been, "It must come to a fight. Only make the right wing strong." Unhappily for Germany, if happily for the world, the younger Moltke, who succeeded him, lacked his moral courage and clear grasp of the principle of concentration. Moltke retained Schlief fen's plan, but he whittled away the essential idea. Of the nine new divisions which became available between 1905 and 1914 Moltke allotted eight to the left wing and only one to the right. True. he added another from the Russian front, but this trivial increase was purchased at a heavy price, for the Russian army of 1914 was a far more formidable menace than when Schlieffen's plan came into force. In the outcome two army corps were taken from the French theatre at the crisis of the August campaign, in order to reinforce the Eastern front.
If the fault of the final German plan was a lack of courage, that of the French plan was due to an excess. In their case, also, a miasma of confused thought seemed to creep over the leader ship in the years just before the war. Since the disasters of 187o the French command had planned an initial defensive, based on the frontier fortresses, followed by a decisive counter-stroke. To this end the great fortress system had been created, and gaps like the Trouee de Charmes left to "canalize" the invasion ready for the counter. But in the decade before 1914 a new school of thought had arisen, who argued that the offensive was more in tune with French character and tradition, that the possession of the "75"—a field gun unique in mobility and rapidity of fire— made it tactically possible, and that the alliance with Russia and Britain made it strategically possible. Forgetful of the lessons of 187o they imagined that élan was proof against bullets. Napoleon's much quoted saying that "the moral is to the physical as three to one" has much to answer for; it has led soldiers to think that a division exists between the two, whereas each is dependent on the other. Weapons without courage are ineffective, but so also are the bravest troops without efficient weapons to protect them and their moral.
The outcome was disastrous. The new school found in Gen. Joffre, appointed chief of the general staff in 1912, a lever for their designs. Under the cloak of his authority, the advocates of the offensive a outrance gained control of the French military machine, and, throwing aside the old doctrine, formulated the now famous, or notorious, Plan XVII. It was based on a nega tion of historical experience—indeed, of common sense—and on a double miscalculation—of force and place, the latter more seri ous than the former. Accepting the possibility that the Govern ment might employ their reserve formations at the outset, the strength of the Germany army in the West was estimated at a possible maximum of 68 infantry divisions. The Germans actu ally deployed the equivalent of 83k, counting Landwehr and Ersatz divisions. But French opinion was and continued to be doubtful of this contingency, and during the crucial days when the rival armies were concentrating and moving forward the French Intelligence counted only the active divisions in its esti mates of the enemy strength—a miscalculation by half ! If the plan had been framed on a miscalculation less extreme, this recognition does not condone hut rather increases its fundamental falsity, for history affords no vestige of justification for a plan by which a frontal offensive was to be launched with mere equality of force against an enemy who would have the support of his fortified frontier zone, while the attackers forswore any advantage from their own.