Answer: The triple alliance and the triple entente prepared the war scenario before World War 1 started.
Step-by-step explanation:
Before World War 1 started, there have been some conflicts that prepared and accelerated the situation.
Two Balcanic wars from october, 1912 to spring from 1913 lightened up the conflict.
Within those years, two blocks were created. The triple alliance formed by The German and Austro-Hungarian Empires and Italy. On the other side, France and Great Britain were allies with Rusia in the triple entente.
The balance started to experience threats because every allie was forced to intervene in a case of agression.