"You may have the universe," composer Giuseppe Verdi once said, "if I can have Italy." Back in the mid-19th century, Verdi's emotive language appealed to the patriotic sentiments of an emergent nation state. After decades of struggle and bloodshed, the movement known as Risorgimento triumphed with the 1861 proclamation of Italian Unity, assembling disparate kingdoms, territories, and borders that had hitherto been ruled by Austria, the Kingdom...