WASHINGTON - The Pentagon (news - web sites) is turning up the heat on the Russian government for ignoring pleas to cooperate in verifying an expanding body of anecdotal evidence that American servicemen from World War II and the Korean War were secretly held in prison camps in Siberia. Russian inaction has made the effort to confirm information about the presence of Americans in the gulag — the network of penal camps that stretched across the former Soviet Union — "a distinctly unilateral U.S. pursuit," Norman Kass, a leader of the Pentagon project, wrote in the introduction to a new...