(14 Feb 1995) STORYLINE: T/I: 11:01:15 The United Nations stepped up its withdrawal of troops from Somalia on Sunday (12/2) as western warships, involved in "Operation United Shield", waited off the coast. With the UN's failed two-year mission to restore peace to Somalia, drawing to a close, 450 Pakistani peace-keeping troops flew out of Mogadishu airport. Marines from the five-ship Italian battle group stationed off the Somali coast are preparing for possible close quarter combat if the