How did the American Revolution influence the French Revolution? Soldiers who had fought on the side of the colonies started the French Revolution.
News of the war introduced the French to the ideas of the Enlightenment.
The war showed that taxation without representation was a just cause.
The colonies’ victory demonstrated that a king could be defeated.

It showed that Enlightenment ideals could be instituted in government

it would be  

germany had to pay all damages related to the war.

and i think

germany had to take sole responsibility for the war.

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.