In the first year of World War One, the German army had pushed so deep into the territory of the Triple Entent and its allies that the Germans had overrun Belgium and most of Eastern France, pushing to within 20 miles of the heart of the French capital of Paris.
In the eyes of the world, a Central Powers victory on the Western Front seemed almost inevitable, and the German army (which had very quickly adapted to the new modern style of industrial warfare) seemed unbeatable. However this was changed by the First Battle of the Marne, wherein Six French Armies as well as an army of the British Expeditionary force repelled the German attackers. The German momentum was broken by the catastrophic defeat and the image of German invincibility was shattered, allowing the Triple Entente to push North East, driving the Germans away from the French capital.
Answer:
d the pollution the industrial north was developing
