
Originally Posted by
Monarchist
Franz Ferdinand was assassinated in Sarajevo. Austria responded by invading that nation in late July, 1914. The "world" war began in early August, 1914. It became global precisely because Russia rushed to defend Serbia, its Slavic neighbour (Nicholas II had been developing a certain love for the Balkans since 1911). This triggered France to respond by mobilizing, as France had made an agreement with Russia to mutually defend each other if one of them went to war. France having declared war on Austria for Austria having declared war on Russia, Germany declared war on France for France having declared war on Austria! This allowed the Germans to start their invasion of France, but they only invaded France via Belgium, which dragged England in because they had a treaty from 1839 vowing to defend Belgium's sovereignty from foreign invasion.
Thus: WWI.