How did the alliance system turn a dispute between two countries into world war i?
leaders knew that if they declared war, their allies had to join the fight with them.
leaders knew that if they declared war, alliances would change quickly.
leaders knew that if they declared war, their allies would do most of the fighting.
leaders knew that alliances would allow them to go to war for unimportant reasons.

Leaders knew that if they declared war, their allies had to join the fight with them.

Explanation:  In the late nineteenth century, many industrialized countries forged alliances and agreements that culminated in the year 1914 in World War I. Germany had gone through the process of unification between 1870-1871, making it a strong, industrialized state; German leader Bismarck defeated France in the Franco-Prussian War (1871). With this defeat, France lost to Russia (the state that led the German unification) as regions of Alsace and Lorraine.

sorry

i do knot know this