A former top aide to Bill Clinton is to plead guilty to removing classified documents from the National Archives. Former national security adviser Samuel Berger has admitted taking copies of a classified memo to prepare for his testimony before the 9/11 Commission. Mr Berger has said it was "an honest mistake" and apologised. He has agreed to give up his security clearance and co-operate with the investigation. The offence carries a maximum one-year prison sentence and a $100,000 fine. 'Inadvertent' behaviour Mr Berger is due to plead guilty before a court in Washington DC. He testified in March 2004 before...