 The <unk> ( AOK ) acknowledged that an undefeated Serbia severed Austria @-@ Hungary 's connection to the Ottoman Empire and prevented the completion of the Berlin – Baghdad railway . The AOK also realized that the Austro @-@ Hungarian Army 's inability to defeat Serbia would discourage neutral countries — such as Bulgaria , Romania and Greece — from joining the Central Powers and would tempt Italy to open up a third front against Austria @-@ Hungary . Nevertheless , the AOK was hesitant to authorize a third invasion of Serbia . This changed in September 1914 , when Austro @-@ Hungarian troops discovered a map in an abandoned Semlin bookshop , titled The New Division of Europe . Originally printed in a Russian newspaper , the map was widely sold in Serbia and depicted the borders of Europe as they would appear following the war . Germany was to be divided into northern and southern confederations and Austria @-@ Hungary was to be abolished , its eastern provinces given to Russia , Romania , the Czechs and the Hungarians , and its southern provinces divided between Serbia and Italy . Alarmed by the prospect of Austria @-@ Hungary 's disintegration , Emperor Franz Joseph personally authorized a third invasion of Serbia in early October 1914 . 
