Though desirous, apparently, of befriending Prussia, he had already yielded to their persistent pleas urging him to stay the growth of the Protestant Power of North Germany.

On June 10, at the outbreak of the war, he secretly concluded a treaty with Austria, holding out to her the prospect of recovering the great province of Silesia (torn from her by Frederick the Great in 1740) in return for a magnanimous cession of Venetia to Italy.

The news of Koeniggraetz led to a violent outburst of anti-Prussian feeling; but Napoleon refused to take action at once, when it might have been very effective.
The best plan for the French Government would have been to send to the Rhine all the seasoned troops left available by Napoleon III.'s ill-starred Mexican enterprise, so as to help the hard-pressed South German forces, offering also the armed mediation of France to the combatants.

In that case Prussia must have drawn back, and Napoleon III.
could have dictated his own terms to Central Europe.

But his earlier leanings towards Prussia and Italy, the advice of Prince Napoleon ("Plon-Plon") and Lavalette, and the wheedlings of the Prussian ambassador as to compensations which France might gain as a set-off to Prussia's aggrandisement, told on the French Emperor's nature, always somewhat sluggish and then prostrated by severe internal pain; with the result that he sent his proposals for a settlement of the points in dispute, but took no steps towards enforcing them.