Final answer:
European nations prepared for war by increasing military spending, enhancing their forces, and stockpiling weapons. They exploited colonial holdings for resources and manpower and used advanced railway networks for troop mobilization.
Step-by-step explanation:
European nations prepared for a potential war by engaging in militarism, which saw an increased focus on military spending and readiness. They participated in an arms race, building up military forces and stockpiling weapons, with a particular emphasis on naval capabilities as seen in the construction of the Dreadnought battleship. To ensure a swift mobilization in case of conflict, extensive European railway networks were utilized to move troops rapidly. Additionally, colonial ambitions and the exploitation of resources played a significant role in the war preparations, most notably in Africa where colonial holdings contributed to the war effort through the supply of both manpower and materials like rubber and tin. Colonial forces, including African and Asian troops, were also mobilized to fight in European armies. The drive for dominance and prestige among European powers not only fueled their preparations but also their imperialistic ventures, further entangling global relations and leading to World War I.