At the turn of the 20th century the development of the new German Empire was having a profound effect on the balance of power in Europe. Intent on increasing Germany's influence on the international scene, to the detriment of the commercial, colonial and diplomatic interests of his neighbours imperial Britain, republican France and tsarist Russia, Emperor William II sent out strong signals such as abandoning the non-aggression pact concluded with Russia by Chancellor Bismarck and making clear his support for greater Austro-Hungarian influence in the Balkans despite the strong Russian presence in the region.

The pact concluded between France and Russia in 1894 increased Germany's diplomatic isolation and the chief of Germany's general staff, Count Alfred von Schlieffen (1891-1906), was quick to understand the threat it posed for Germany in the advent of war: with belligerents on either side, the German Empire could quite easily be held in a vice-like grip between the troops of Tsar Nicholas II and the French Army, the latter thirsty for revenge after the defeat of the Franco-German war of 1870-71.

Schlieffen's careful study of the opposing forces led him to conclude that any plan should aim to knock out the French Army before taking on Russia in the east which, although endowed with a large and powerful army, would need at least six weeks to assemble its troops from across its vast territory. In light of this, Schlieffen proposed to concentrate German troops on the Western Front so that they could execute a swift victory over the French before turning their full attention to the Eastern Front. The desire for a brief war was also motivated by the reason that, unlike France or Great Britain, Germany had no colonial resources on which she could draw to support the war effort.

As Schlieffen said himself, "We must penetrate the fortress of France through the sector between Mézières and Dunkirk. We must attack the French left flank incessantly and endeavour, without respite, to drive them back to Jura and Switzerland". Although France and Germany shared a border in the region of Alsace, the sector did not lend itself to being the theatre of a massive attack for three main reasons. Firstly, it was a rural mountainous zone with poor communications which rendered the movement of troops and equipment difficult. Secondly, it was heavily defended: after the annexation of Alsace by Germany in 1871, France instructed military engineer Raymond Seré de Rivières to build a series of forts along the frontier from Belfort to Verdun and it was in these forts that the French Army concentrated a large number of its soldiers in readiness for any hostile actions by the Kaiser's troops. And finally, an attack launched in the area would threaten the mining and industrial activities of the state of Saarland which was certain to find itself in the path of any French advance into Germany.

Considering, like Chancellor Bethmann-Hollweg, that the treaty of 1851 which recognized Belgian neutrality was nothing but "a scrap of paper", the German general staff planned to sweep through Belgium and enter France through its northern border and the region of Ardennes. From there, the Germany Army would only have to cross the plains of Picardy to capture Paris and then head east to attack the French Army's rear. At the same time, German forces would be able to seize control of the various industries and mines in Northern France and put the well-developed rail and road network there to their use.

Schlieffen's plan called for an attack between Dunkirk and Verdun with thirty-five army corps and eight cavalry divisions; however, after securing the unanimous support of the German general staff for his plan, he retired in 1906 and left its execution to his successor General Moltke. The latter decided to modify the plan by maintaining two armies in Alsace and thus reduce the number of troops available to launch an attack on Belgium and Northern France.

Many historians see this change of plan as the principal cause of the failure of the Schlieffen Plan which Germany enacted on 4 August 1914, the day after declaring war on France. Contrary to all expectations, the German Army came up against some determined resistance from the Belgian Army, especially at Antwerp and Mons. William II and Moltke were also surprised by the reaction of the British government when it declared war on Germany as soon as it was clear that Belgian neutrality had not been respected. On 7 August, under the command of the aptly named General French, a British Expeditionary Force (BEF) of 75,000 men landed on the European mainland with orders to stop the German advance in Belgium and France. The BEF supported the Belgian Army in the Battle of Mons (23 August) and, during its withdrawal to France, slowed down the progress of the German Army at the Battle of Le Cateau (26 August 1914). Meanwhile on 25 August, French forces began the stern defence of the fortified town of Maubeuge and this resulted in a prolonged siege which diverted 60,000 German soldiers from their main objective of Paris.

The First Battle of the Marne, which opened on 5 September, put an end to the Schlieffen Plan: the French Army had had time to regroup its troops and was waiting in readiness to defend Paris. It had become clear that the war would not be a short one and the German Army would be obliged to fight on two fronts, Belgium and France in the west and Russia in the east.

General Moltke was subsequently removed from his post at the head of Germany's general staff and replaced by General Falkenhayn.

Didier PARIS, Professor of History, and Edouard ROOSE