jevo by a Bosnian Serb ['the cause']. In retaliation, Austria declared war on Serbia, launching the sequence of events that culminated in World War I ['the effect']." In fact, both the assassination of Franz Ferdinand and even Austria's declaration of war against Serbia are but two relatively minor variables within the far larger set of complex issues that contributed to the many causes of World War I. While Franz Ferdinand's assassination may have been the immediate catalyst of the war, it was certainly not the cause.