After the Austro-Prussian War, Austria was required by Prussia to ceede Venetia to thier ally Italy. However, Austria had beaten Italy in every respect and battle (except one where they were outnumbered 2 to 1) in thier theatre and refused to directly ceede Venetia to Italy. Therefore it was proposed that Venetia would be ceeded to France (who was a supporter of Italy and would likely just give it to them).
What would happen if Napoleon III had decided to just keep Venetia?