The conflict between Prussia and France existed even before the Austro-Prussian War, when Napoleon III thought Austria could easily defeat Prussia and chose to remain neutral.
Unexpectedly, Prussia not only defeated the Austrian Empire but almost unified Germany, which alarmed France.
Napoleon III immediately accepted Emperor Joseph I's request to mediate the war, refusing to watch Prussia expand its victories.
Bismarck noted Napoleon III's neutrality and then mediation, and the grudge was noted down; currently, Prussia was not yet a match for France in direct confrontation.
The growing power of Prussia would inevitably threaten France's position on the Western Continent, as these two nations have been adversaries since Napoleon's era.
After Napoleon breached Berlin, he remained a vulgar conqueror, personally desecrating Frederick the Great's tomb in Potsdam, and sent Frederick the Great's sword and scarf back to the Military Academy in Paris.
