What are the reasons for the failure of the lightning war? What are the results of the 1914 campaign?

We are talking about disrupting the Schlieffen plan, which the Germans developed in 1913. He envisioned a quick victory over France, and then the defeat of Russia in the east.

As a result, the French during the Battle of the Marne, with their stubborn resistance, were able to stop the German offensive, and the Russian army carried out an unsuccessful operation in East Prussia (now the Kaliningrad region and neighboring regions of Poland), which distracted part of the German army.

Results of the 1914 campaign:

-The Germans lost Qingdao in China and Togo in Africa.

-Turkey entered the war on the side of Germany.

-The Austrians could not break Serbia.

-France lost part of the territories in the northeast, but the Germans got bogged down in trench warfare.

-Belgium was almost entirely occupied.

-Russia was able to capture part of Austria-Hungary (Galicia), but lost some territories to the west and south of Warsaw, for example, Czestochowa and Kalisz.