What was the primary cause of World War I?

The assassination of Archduke Franz Ferdinand in 1914 serves as the catalyst that ignited the complex web of alliances and tensions among European powers, ultimately leading to World War I. This event triggered a series of diplomatic crises and mobilizations among nations, setting off a chain reaction. The assassination was carried out by a member of a nationalist group seeking independence for Bosnia from Austro-Hungarian rule.

Following the assassination, Austria-Hungary issued an ultimatum to Serbia, which, although partially accepted, led to the declaration of war by Austria-Hungary against Serbia. As countries honored their military alliances, the conflict quickly escalated. The situation was fueled by pre-existing rivalries, militarism, and nationalism, but the assassination was the immediate event that set everything into motion.

Understanding this historical context helps illustrate why the assassination of Archduke Franz Ferdinand is identified as the primary cause of World War I, highlighting its role as the trigger for a broader and more complex conflict.