Why, after the defeat of Austria, Bismarck also needed a victory over France? did France somehow

Why, after the defeat of Austria, Bismarck also needed a victory over France? did France somehow interfere with the unification of Germany under the rule of Prussia?

Diplomacy in European countries developed in such a way as to hinder, as far as possible, their neighbors from expanding their power and territory. France was entirely satisfied with the role of Germany as a divided state, and the unification of such militarized countries as Prussia and Austria could seriously harm France, since many of the territories belonging to her at that time were controversial, such as Alsace and Lorraine, because of which later the First World War began.