What was the biggest impact on World War 1?

The biggest impact on World War I was the profound shift in geopolitical power and the emergence of new political ideologies. The war led to the collapse of empires such as the Austro-Hungarian and Ottoman Empires, redrawing national borders and creating new nations. Additionally, the war fostered the rise of totalitarian regimes and set the stage for World War II due to unresolved tensions and the harsh terms of the Treaty of Versailles. The societal changes, including shifts in gender roles and the influence of technology in warfare, also had lasting effects on the world.