Joschka Fischer, Germany’s foreign minister and vice-chancellor from 1998 to 2005, was a leader of the German Green Party for almost 20 years. The Franco-German relationship has always been complicated and never free of conflict or tension. Everyone understands that co-operation between these two key European Union countries is necessary and in the interest of the entire bloc. Nonetheless, they have never fully overcome their current – and historic – rivalry. One reason is that France and Germany are equally strong, albeit in different dimensions. Over the past seven decades of gradual European unification, Germany – though divided between 1945...