Walter Mondale, a former U.S. vice president and ambassador to Japan who worked on a yet-to-be-realized plan to close a key U.S. air base in Okinawa Prefecture, died Monday at his home in Minneapolis, according to U.S. media. He was 93.The death of Mondale, known as a champion of liberal politics, was announced by a family friend and spokeswoman Kathy Tunheim but no specific cause was provided, according to The Washington Post.Mondale was U.S. ambassador to Japan from 1993 and 1996 under the then administration of Bill Clinton, after serving as vice president to Jimmy Carter for four years …READ FULL ARTICLE