Question

question 3
how did the alliance system in europe contribute to the start of world war i?
the alliance system forced great nations to go to war when their allies did.
the alliance system helped nations secure their national treasuries.
the alliance system was a failed attempt at diplomacy to keep the peace.
the alliance system kept nations divided politically promoting hostility.

Explanation:

The alliance system in Europe during that time meant that when one nation went to war (e.g., after the assassination of Archduke Franz Ferdinand, Austria - Hungary declared war on Serbia), its allies were bound by treaty to join the conflict. This created a domino - effect. For example, Russia (an ally of Serbia) mobilized, which led Germany (an ally of Austria - Hungary) to declare war on Russia and then on France (an ally of Russia).

Answer:

The alliance system forced great nations to go to war when their allies did.