Final answer:
European militarism prior to World War I reduced the effectiveness of diplomacy in resolving disputes as nations relied more on military strength over peaceful negotiations, leading to the Great War.
Step-by-step explanation:
Prior to World War I, militarism in European nations significantly impacted the art of diplomacy and resolution of disputes. As nations amassed large armies and advanced naval fleets in an arms race for supremacy, diplomacy often took a back seat. The build-up of military forces, along with an ever-present readiness for mobilization, meant less time for calm, diplomatic decision-making and an increased likelihood for rapid escalation into conflict.
The European alliances and the delicate balance of power that had kept wars limited were now under strain as countries like Great Britain and Germany locked into a naval arms race, epitomized by the construction of the Dreadnought-class battleships. The aggressive push for military buildup by these nations, coupled with Germany's desire for expansion and colonization, brought an element of fear and suspicion among the great powers. Instead of seeking resolution through dialogue and negotiation, nations became more inclined to use the threat of military might to achieve their goals - a practice which ultimately reduced the effectiveness of diplomacy in maintaining peace and led to the catastrophe of the Great War.