I disagree with the point on the Austro-Prussian War. Virtually everyone expected Austria to win; it shocked the world when Prussia suddenly won in just a few weeks. There was no time for France to intervene, not when it was already busy elsewhere; the whole thing was over too quickly.
The Franco-Prussian War, on the other hand… that was stupid. His arny was grossly unprepared, he'd just seen a clear example of how excellent the Prussian army was, and when given a choice between obeying the newspapers or avoiding a disastrous war he chose to obey the newspapers. He could have resisted the public pressure and followed his own established policy of "L'Empire, c'est la paix" (basically "honest, guv, I'm not as violent as Napoleon I") but he chose not to. That choice destroyed him.
Alternatively, I'd suggest his proposal to Bismarck that France might take some of western Germany as part of a bargain with Prussia. Bismarck promptly leaked it to Bavaria, Württemberg, Hesse and Baden and thus got them on his side out of terror of French expansion. But I think that entering the Franco-Prussian War was sillier.