Plan XVII

Plan XVII was the name of the battle plan adopted by the French General Staff in 1913, to be put into effect by the French Army in the event of war between France and Germany. When Germany declared war a year later, France riposted with five initiatives, now collectively known as the Battle of the Frontiers:

# Battle of Mulhouse - (7-10 August 1914)
# Battle of Lorraine - (14-25 August 1914)
# Battle of the Ardennes - (21-23 August 1914)
# Battle of Charleroi - (21- August 1914)
# Battle of Mons - (23-4 August 1914)

The battles relied on the principle of "élan" ("dash", in the sense of prompt, spirited and vigorous action). The French commander in chief, General Joseph Joffre, was one of the main architects of Plan XVII.

Background

Following the defeat of the French armies during the Franco-Prussian War of 1870-71, the French military had to adapt to a new balance of power in Europe. The emergence of the German Empire on the other side of the Rhine, combined with the loss of the provinces of Alsace and Lorraine, had the effect of putting France at a disadvantage.

In 1898, the French General Staff adopted Plan XIV. Taking into account the numerical inferiority of the French Army, plan XIV was a defensive strategy along the Franco-German border. Besides the increasing disparity in population (by the turn of the century France had a stagnant population of around forty million, compared to fifty million Germans) there was also the problem of reserves. The war of 1870-71 had demonstrated ability of the German General Staff to make use of the German railroad network to deploy its armies and its capability to quickly mobilize its reservists into front-line units. While the French General Staff began to apply the lessons of the use of railways, the question of using reservists in frontline units was not resolved. Plan XIV didn't take reserves into account.

In 1903, Plan XIV gave way to Plan XV. While defensive in character Plan XV considered using reserve formations but in a subordinate role.

The offensive French military strategy in World War I known as Plan XVII was created by Ferdinand Foch. The offensive plan used brute force and a mystical belief in "élan" or "fighting spirit." General Joseph Joffre adopted this plan upon becoming commander-in-chief in 1911.

After the Franco-Prussian war of 1870, the French had lost the provinces of Alsace-Lorraine to the German empire. This created a spirit of revanchism amongst some people in France. One aim of Plan XVII was to recapture Alsace and Lorraine. Four French armies would advance on either side of Metz and Thionville. This left only one army to defend northern France but French planners were convinced that Germany would not invade through Belgium, as this would lead to British involvement (in the Treaty of London, the United Kingdom had guaranteed Belgian neutrality).

The Germans regarded the Treaty of London as a mere "scrap of paper" (and thought the British would do so as well). Their strategy, the Schlieffen plan, was an attack through Belgium and northern France to encircle Paris.Unfortunately for the French, a reconnaissance by the French Cavalry Corps under General Sordet, confirmed Joffre's belief that the Germans couldn't be strong in Alsace-Lorraine, and defend against the Russians, yet still invade in strength through Belgium. So Joffre discounted this, not realizing that it was the Russian frontier which was relatively weak, and that the invasion of Belgium was still developing.

Plan XVII failed. The German defense of Alsace-Lorraine turned out to be much better than expected and within a few weeks, the French were back in their starting positions, while the Germans had advanced almost unopposed through Belgium and northern France and were threatening Paris, executing the Schlieffen Plan. Only the fact that the German high command diverted troops to the Eastern Front and to a counterattack in Alsace-Lorraine (which was in turn repulsed by the French), allowed the French and their British allies (who had adhered to the Treaty of London and thus declared war on Germany after the German invasion of Belgium) to halt the German advance in the First Battle of the Marne. With hindsight, the failure of Plan XVII may not have been an entirely bad thing. The original Schlieffen Plan had little defense in Alsace-Lorraine in order to lure French forces away from Paris into Germany, then to be double-enveloped and destroyed. The failure of the French to take Alsace-Lorraine might have eventually earned them their victory on the Marne.

External links

* [http://www.firstworldwar.com/maps/warplans.htm "First World War.com" A map of the French and German war plans]
* [http://www.firstworldwar.com/features/plans.htm "First World War.com" French and German war plans]