The Franco-German War of 1870-71 had far-reaching consequences. It established both the German Empire and the French Third Republic and set in train the alliances that had formed when Germany first declared war on Russia in August 1914. The monarchies of all four of the great powers, Britain, Russia, Austro-Hungary, and Germany, were either unprepared for leadership, too old or irrational and easily manipulated by a small coterie...