Both alliances were formed so that if they were attacked, their allies would help them. This however led to the start of WW1 due to the secret treaties and alliances.
It all starts with the assiantion Archduke Franz Ferdiand by Phillp Princpes,A member of the nationalist Serbian group the black hand.The Archduke was the heir to the Austro-Hungaruan empire hand been sent to Bosnia to strengthen the loyalty of the bosinan people to the empire. Austria-Hungary is outraged and demands the right to send troops to serbia and demands compensation. The Serbian government