U.S. defense secretary nominee undergoes back surgery

By Will Dunham WASHINGTON (Reuters) - Ashton Carter, President Barack Obama's nominee to replace Chuck Hagel as U.S. defense secretary, has undergone a long-planned surgical procedure on his back ahead of his confirmation process in the Senate, the White House said on Friday. White House spokesman Josh Earnest said in a statement that the procedure was successful but did not give details about the operation. "Mr. Carter decided to go ahead with the previously scheduled procedure so tha