The Austro-Hungarian Empire.
In June 1914, the heir to the Austrian throne was murdered in Sarajevo, by Bosnian nationalists- Bosnia was ruled by the Austro-Hungarian Empire at the time, and Sarajevo is Bosnia's capital city. These nationalists were believed by the Austrian government to have been supported by intelligence agents from nearby Serbia, a country Austria already didn't like (and vice versa). Serbians and Bosnians are related ethnic groups, so Serbia (supposedly) wanted to help their Bosnian cousins break away from Austria.
After the assassination, Austria issued a list of demands to the Serbian government, saying that if Serbia did not accept allof them, then Austria would attack. Serbia accepted all but one (from what I understand, the Serbian constitution at the time forbade them from accepting it), and Austria declared war on Serbia, which began World War I.
Because Germany wanted war with Serbia.
Austria-Hungary attempted to invade Serbia during World War One.
Hitler and the NAZI party wanted a world without Jews involved so they declared war on the world and almost won
Austria wanted to crush Serbia and they brought France Germany Russia and Britain into the war
because he was a prince and the assassin was from Serbia and Frank's family and friend and his people wanted the congress to declared war on Serbia and congress did so Serbia declared war on another country
the war of serbia and kasvo was going on because serbia wanted more
Because Serbia for example wanted to be its own nation from Austria-Hungary.
who was the first country to invade in world war 2
The war between Serbia and Kosovo was going on. The war started because Serbia wanted more territory from Kosovo.
they promised to support Austria-Hungary after it threatened to invade Serbia
they promised to support Austria-Hungary after it threatened to invade Serbia
Serbia was in WWI because Austria-Hungary declared war on them.