<P> Overlaying this was a culture of extreme nationalism, and a cult of assassination, derived from the slaying of the Ottoman Sultan as the heroic epilogue to the otherwise disastrous Battle of Kosovo on 28 June 1389 . Clark states: "The Greater Serbian vision was not just a question of government policy, however, or even of propaganda . It was woven deeply into the culture and identity of the Serbs". </P> <P> Serbian policy was complicated by the fact that the main actors in 1914 were both the official Serb government led by Nikola Pašić and the "Black Hand" terrorists led by the Head of Serb Military Intelligence, known as Apis . The Black Hand believed that a Greater Serbia would be achieved by provoking a war with Austro - Hungary through an act of terror which, with Russian backing, would be won . </P> <P> The official government position was to focus on consolidating the gains made during the Balkan war, and avoid any further conflict, since recent wars had somewhat exhausted the Serb state . Nevertheless, the official policy was muted by the political necessity of simultaneously and clandestinely supporting dreams of a Greater Serb state in the long - term . The Serb government found it impossible to put and end to the machinations of the Black Hand for fear it would itself be overthrown . Clark states: "Serbian authorities were partly unwilling and partly unable to suppress the irredentist activity that had given rise to the assassinations in the first place" </P> <P> Russia, for its part, tended to support Serbian as a fellow Slav state and considered Serbia her "client". Russia also encouraged Serbia to focus its irredentism against Austro - Hungary because it would discourage conflict between Serbia and Bulgaria (another prospective Russian ally) in Macedonia . </P>

What were the causes for world war 1