BERLIN   German Chancellor Friedrich Merz has called Berlin’s exit from nuclear energy a "serious strategic mistake" and criticized previous governments for hastily shutting down the country's last atomic reactors. Speaking at a business conference in Saxony-Anhalt late Wednesday, Merz directed sharp criticism at the energy policies of his predecessors, including former Chancellor Angela Merkel, for creating the world's costliest energy transition. "It was a serious strategic mistake to exit