What are the short-term causes of World War I?
The short-term causes of World War I were the assassination of the Archduke Franz Ferdinand, Austria-Hungary's decision to take a hard line with the nation of Serbia in response, and the alliance systems that caused the local conflict in the Balkans to spread throughout the continent.
The Archduke was the heir to the throne of the Austro-Hungarian Empire, and though he was reform-minded, he was killed by Gavrilo Princip, part of a Bosnian Serb group eager to create a pan-Slavic state under the control of Serbia. With German leaders goading them along, Austria-Hungary held the state of Serbia responsible for the assassination, issuing a deliberately provocative ultimatum for the Serbians to turn over the parties responsible for conspiring to assassinate the Archduke. When Serbia refused, Austria-Hungary declared war, and the complex alliance systems that had developed over the previous three decades kicked in. Serbia's ally Russia mobilized its forces against Austria-Hungary, and Germany in turn declared war on Russia. A complex series of events followed that saw Russia's ally France declare war on the Russians, and when Germany went through Belgium to attack the French, Britain entered the war to fulfill their treaty commitment to defend the Belgians. With that, the nations of Europe were sucked into what would become the most destructive war any had ever experienced.