Why did WW1 become a global war?

World War I became a global war primarily due to the intricate system of alliances that linked various nations, meaning that a conflict involving one country could quickly escalate to involve others. The war began in Europe but spread to other continents as countries like Britain, France, and Germany had colonies and allies worldwide. Additionally, the involvement of the United States and other nations further expanded the conflict, making it a truly global struggle. The ramifications of the war and the treaties that followed also had lasting international impacts, shaping future geopolitical dynamics.