An influential advisory panel to Defense Secretary Robert Gates has recommended a new six-point plan, with a $4 billion annual price tag, to deal with one of the most vexing national security challenges -- protecting the United States against weapons of mass destruction. The Defense Science Board, in a task force report dated May 2007 and made public today, is recommending what it calls a "full spectrum" program to reduce U.S. vulnerability to chemical, biological, radiological and nuclear weapons, including...