World War I: Trench Warfare and Shifting Fronts

Development of Conflict: War, Trench Warfare, and Movements
Germany and Austria-Hungary possessed powerful armies and benefited from geographically dispersed enemies, allowing for easier communications. However, a two-front war was required for a swift victory. Conversely, the French and British naval blockade could isolate them. The German plan involved a rapid strike against France, advancing through Belgium and Luxembourg. France was expected to capitulate, enabling the Central Powers to focus their efforts on the Russian front. Germanic armies advanced into France, invading Belgium unopposed. In September 1914, German forces were within 40 miles of Paris. The French armies managed to halt the German advance at the Battle of the Marne. The German blitzkrieg had failed. The French stabilized their defensive positions, establishing a front line from the Swiss border to the North Sea. On the Eastern Front, Russian forces invaded Austro-Hungarian territory. On the Western Front in 1916, the Germans initiated the Battle of Verdun, where French soldiers withstood the attacks. The Entente also attempted an offensive on the Somme, but it was unsuccessful. On the Eastern Front, a new Austro-German offensive recaptured territories occupied by the Russians the previous year, securing Russian Poland and Lithuania.
The Crisis of 1917 to the End of the War
In 1917, the war seemed endless. Hunger and misery pervaded the home fronts, and patriotic enthusiasm waned. Protests, widespread strikes, and criticism of Army Staffs became common. Mutinies and desertions occurred at the front. The outbreak of the Russian Revolution and the Bolsheviks' rise to power altered the situation. The new Soviet government requested an armistice and signed the Treaty of Brest-Litovsk with the Central Powers in March 1918. Russia ceded Ukraine, Poland, Finland, Estonia, Latvia, Lithuania, and Belarus. Romania ceded Bessarabia, and part of Armenia was ceded to Turkey.
In 1918, on the Balkan front, between September and October, British, French, and Italian forces defeated the Turks, Bulgarians, and Austrians. The Ottoman Empire and Austria-Hungary requested armistices, halting the fighting. Hungary severed ties with Austria, and Croats proclaimed their independence. On November 3, the Austrian Empire surrendered.
On the Western Front, the Germans utilized the withdrawal to launch a final offensive. However, the Entente, reinforced by American aid, achieved a decisive victory at the Marne, forcing the German army's retreat. The Reich began to collapse: the navy mutinied at Kiel, and a revolution erupted. William II abdicated, a republic was proclaimed, and the new government signed an armistice.