Austria-hungary attacked Serbia
Serbia assassinated arch duke Ferdinand Austria attacked Serbia Russia attacked Austria because they were allied to Serbia Germany attacked Russia because Germany was allied to Austria France and England were allies of Russia, so Germany attacked France France was then in war with Germany
mostly Serbia
It fought against Germany-AustroHungary. The rise of Bolsheviks and Mensheviks established a Communist government which was attacked by the old regime (White Russian) forces supported by Britain ad France, which ensured the World War extended past its official end date of 1918 to 1921 in the Russian east.
The archduke of Austrohungary Franz Ferdinand was assassinated in Serbia. The Serbians arrested the assasin and Austrohungary asked Serbia to deport him. The Serbians refused, so Austrohungary invaded Serbia and another country got involved and another and so on until it finished up a world war.
If you mean how did alliances cause WWI, it was because when one country attacked another, each ally had to fight for the first, which made more people angry Serbia provoked Austria Austria attacked Serbia Russia was allied to Serbia, so they attacked Austria Germany was allied to Austria so they attacked Russia's allies, France and England
They attacked Serbia as it was clean and peaceful so it wasn't reliable on America until they bombed Serbia
because the assaination of Franz ferdinand who was the prince of austo hungary at the time caused so much tensions between the austohungary and serbia. The both made alllies. One side was the central powers with austrohungary italy ottoman empire and germany. The allied powers where france england russia serbia belgium
Zombies attacked.
Many events happen in Serbia every day. Please ask a specific question.
ANSWER The main reasons were followings: 1 - because they were found humiliating and damaging the independence of Serbia; 2 - because Serbia was backed by Russia (which had pledged its intervention in case of Austria had attacked Serbia), in rejecting the demands.
Civil war