Answer:
The French stopped the German advance in the west
Step-by-step explanation:
In 1914, Europeans thought the war would be short. But the generals, who had studied the Napoleonic wars, were wrong in their initial approach to the confrontation, based on the massive use of infantry. Responding to the enormous effectiveness of weapons such as rifles, automatic weapons and heavy artillery, the fortifications were reinforced.
At the beginning of the war the two sides tried to obtain a quick victory by means of fulminating offensives. The French grouped their troops on the border with Germany, between Nancy and Belfort, divided into five armies. The Germans had a much more ambitious plan. They were counting on the speed of a contour movement through Belgium to surprise French troops and march east of Paris and then confront enemy forces and push them towards Jura and Switzerland. They only placed 2/7 of their troops on the border to resist the frontal attack in Alsace-Lorraine.
European military alliances in 1915.
The beginning of the plan went perfectly for the Reich. His troops advanced on Belgium on August 4, which prompted English intervention. They subsequently defeated the French army in various battles. The French simultaneously launched Plan XVII, but it was a failure due to automatic weapons that halted any assault and a premature withdrawal of troops to their lines. Weeks later the Germans were already located on the Marne River, where they collided with the British Expeditionary Force (BEF) and the French army, which slowed the imperial advance. The German defeat frustrated the original plan and ended the expectations of a brief conflagration, marking the definitive abandonment of the pre-war plans. At that moment the "race to the sea" began: the two armies marched towards the North Sea; attacks and counterattacks followed. The contest would take place in French and Belgian territory. British troops soon intervened in greater numbers, along with the remains of the Belgian army.