Do you think the war with France in 1870-1871 was necessary to complete the unification of Germany?

Definitely, this war was needed by Prussia. After the Austro-Prussian War, the authority of Prussia among the German states was extremely great. However, it was necessary to prove that the victory in the war was not a one-time success, but the pre-planned, well-coordinated actions of the Prussian government. And the Franco-Prussian war had to prove it. Also, do not forget that Alsace and Lorraine were in the possession of France, which from ancient times were German lands and without them the unification of Germany would not be complete.