The West Wing1999

Glenallen Walken:
Franz Ferdinand, who was the nephew of the Austro-Hungarian emperor, was killed by a group called the Black Hand. And because they were a Serbian nationalist society, the empire declared war on Serbia. Then Russia, which was bound by a treaty, was forced to mobilize, which meant that Germany had to declare war on Russia. Then France declared war on Germany, and that was World War I. Because the emperor's nephew was killed.