The United States brought fresh troops and resources to the Allied cause and helped to turn the tide of the war in their favor.
2) The Russian Civil War that followed the Russian Revolution in 1917 also had a major impact on the war.
The Russian withdrawal from the war left Germany with a clear advantage on the Eastern Front, allowing them to focus their efforts on the Western Front.
3) The development of new military technologies such as tanks, airplanes, and submarines also played a significant role in the war.
These new technologies allowed for more effective and efficient warfare and helped to break the stalemate of trench warfare.
4) The economic blockade imposed by the Allies on Germany was also a key factor in the war.
The blockade cut off Germany from its supplies and resources and made it difficult for them to continue the war.
5) The war had a devastating impact on the civilian population of Europe. Millions of people were killed or injured, and millions more were displaced from their homes.
The war also led to widespread economic and social disruption, which set the stage for the rise of authoritarian regimes in Europe in the 1920s and 1930s.