The main causes of World War I can be attributed to a complex web of factors that included nationalism, imperialism, militarism, and the system of alliances between different countries. Specific events that led to the outbreak of war include the assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist, and the subsequent diplomatic crisis that arose between Serbia, Austria-Hungary, and the other major European powers. Military mobilization by various nations and a failure of diplomatic efforts to prevent the conflict further escalated tensions, ultimately resulting in the outbreak of war in 1914.
