How did the alliance system deepen the original conflict between austria hungary and serbia?

The Alliance System forced more countries to participate into war against the other countries which lead to World War I. After the assassination of the crown prince of Austria-Hungarian empire, Austria-Hungary declared a war against the small Kingdom of Serbia. Slavic Russian, which was an ally of the Kingdom of Serbia, then, declared war against Austria-Hungary and caused the Germans, French, and British to join in on the war.