U.S. Defense Secretary Jim Mattis told participants in a 20-nation ministerial meeting on North Korea that the United States has already prepared a war plan for the North in case diplomatic efforts fail, a source from one of the countries said Wednesday.The source said Mattis made the remark at a welcome dinner in Vancouver on Monday for the foreign ministers and other officials from the countries including Japan, South Korea and nations that backed the South in the 1950-1953 Korean War.Mattis appealed to the attendees to make progress on the North Korea issue at their meeting on Tuesday, s…READ FULL ARTICLE