Joffre Moves France from Plan XVI to Plan XVII

General Joseph Jacques Césaire Joffre and His Wife
in 1911, the Year He Became Chief of Staff 

Following the disastrous defeats of the French Army in 1870 and 1871, there was a complete reorganization of the French military establishment. In 1887, after the completion of the strong defensive areas close to the frontier, the conservative, defensive policy was discarded. In Plan VIII, a general offensive was to be directed against Alsace-Lorraine with the recovery of these lost provinces as the initial and primary objective. Thereafter, throughout the succession of plans, the offensive was the keynote of French strategy.  

Plan XVI

In 1911, the relations between France and Germany were close to the breaking point. Plan XVI, then in force, established the main French assembly area near the German frontier preparatory to invading Alsace-Lorraine, and took little account of the possibility of a German attack from the north—the very plan which had already been adopted by Germany. General Michel, Vice President of the Superior War Council, thought Plan XVI fraught with danger. As the result of the maneuvers in 1910, he was convinced that the Franco-German frontier was unsuitable for decisive operations and concluded that the main conflict would be fought farther to the north. He submitted to the Minister of War a plan calling for a regrouping of the French armies by concentrating 1,000,000 men between Lille and Rethel and correspondingly reducing the forces along the Franco-German frontier. This plan did not abandon taking the offensive at  the start of the war but did contemplate such an offensive being made toward Germany through Belgium.

For various reasons, important ones of which were the proposed drastic reorganization of the army at what appeared to be a critical period, and a slower mobilization resulting from reorganization, Michel's plan was not adopted. His post of Vice President of the Superior War Council was abolished, and a new post, that of Chief of the General Staff of the Army, was created, of which the incumbent automatically became commander-in-chief in time of war.

General Joffre was appointed Chief of Staff on 28 July 1911. He was a veteran of the War of 1870, with a long record of distinguished accomplishment. Since 1909, he had been a member of the Superior War Council and Director of the Services of the Rear, a post which had given him ample opportunity to become familiar with the problems of mobilization, transportation, and supply. Without friction but with great firmness, as Chief of Staff, he dominated the Superior War Council. His decisions were rarely questioned and never disapproved and he became France's supreme military authority. He prepared a new war plan, Plan XVII, which  controlled the concentration and early operations of the French Armies in 1914 as Chief of Staff, he dominated the Superior War Council. His decisions were rarely questioned and never disapproved and he became France's supreme military authority. He prepared a new war plan, Plan XVII, which controlled the concentration and early operations of the French Armies in 1914.

1905 Schlieffen Plan in Concept

Plan XVII

The MISSION of the French Armies was . . . to defeat the German Armies in order to regain the "Lost Provinces", and to regain the prestige of France as a military power which was lost during the Franco-Prussian War. The initial PHYSICAL OBJECTIVE was to regain Alsace and Lorraine. Defensive operations, alone, could not attain this objective; hence, from the outset, the campaign was to be offensive In CHARACTER. Furthermore, an agreement had been reached with Russia in 1911 to the effect that in the event of war, the French and Russian armies would cross the frontiers on the sixteenth day after mobilization and would pursue a vigorous offensive.

The reorganization of the Russian army and a closer understanding with the British General Staff—developments during the period since Plan XVI had been adopted—gave rise to the belief that France could reasonably expect more cooperation from Great Britain and Russia. Improved diplomatic relations with Italy indicated that the latter country might be  unwilling to join Germany and Austria against Great Britain and France. This permitted some modification in plans for defense of the Franco-Italian border.  Improved railway communications In eastern France permitted concentration of troops closer to the German frontier. On the  other hand, the German railways had been improved near the Belgian border and there were other indications which might have led to the belief that Germany planned to march across Belgium.

General Joffre believed that the French and German armies would assemble face to face, separated at most by a few days' march, and that heavy fighting would follow almost immediately after mobilization, and also that the war would be of short duration. With reference to a German invasion of Belgium, Joffre did not believe that they would go north of the Meuse because such a move, it was thought, would make the attack too weak by over-extension of the front.

In considering Courses of Action open to France, Joffre advocated, in 1912, a French advance through Belgium and Luxembourg, pointing out the advantages of taking the initiative in that direction, and suggesting that it night be feasible to make previous arrangements with Great Britain and Belgium for this action. This was vetoed by President Poincare because it would probably align Belgium against Prance and would surely alienate Great Britain. In fact, in November 1912, Sir Henry Wilson, Chief of Staff of the British Armies, notified Joffre that Great Britain would join Germany if France violated Belgium's neutrality. Such action would be very disadvantageous to France—the consequences as to cost would be too great; on the other hand, the violation of Belgium's neutrality by Germany would surely bring Great Britain and Belgium to France's aid—a great advantage to the latter country.

Click on Image to Enlarge

General Joffre's DECISION, following the tradition of Plan XVI and its predecessors, was to concentrate the main body of the French armies in the region of the German frontier with a view to taking the offensive into Alsace and Lorraine upon the completion of the concentration.  It will be noted that Plan XVII was a plan of CONCENTRATION rather than a plan of OPERATIONS. Whereas the German Plan actually prescribed the operations to be undertaken, the French plan left the Commander-in-Chief freedom to take such action as might be indicated by the situation after the concentration had been completed.

The provision of a strategic reserve so located as to permit its use to assist in opposing a German advance against either flank was intended to increase his Freedom of Action. Upon completion of the concentration, on the 13th day of mobilization, Joffre declared in general terms his intention to take the offensive, as follows: 

Whatever the circumstances, it is the Commander-in-Chief's intention to advance with all forces united to the attack of the German armies. The action of the French armies will be developed in two major operations: one, on the right, in the country between the wooded district of the Vosges and the Moselle below Toul, the other, on the left, north of the line Verdun-Metz.  These two operations will be closely connected by forces operating on the Haute de Meuse and in the Woevre.

In following this plan, it was hoped to secure such initial successes as to imperil the German armies in the north. If the French attacks proved unsuccessful, a defensive stand would be made on the fronts Bclfort-Nancy-Verdun-Charleville. Should this line give, a further stand could be made behind the line of the Aisne, the Oise, and the Somme. It was also expected that Russian attacks on the Eastern Front would necessitate the withdrawal of German forces from the west and thus weaken that front so as to permit the chance of a decisive defeat of the Germans there. 

Joffre as Victor of the Marne

Plan XVII was the plan with which France went to war in 1917.  It would fail dramatically, but before the weaknesses of the Schlieffen Plan became clear to the German High Command.  Joffre thus had a time advantage for developing a new strategy—which would fortuitously bear fruit on the Marne in September 1914.

Source:  "Military Strategy of the World War", U.S. Naval War College, 1938