Russian President Vladimir Putin, who is running for a fifth term in office this week, has over the past two decades built up a system of domestic repression and confrontation with the West that is almost certain to guarantee his re-election.

Ever since the previously little-known KGB agent became president, on New Year's Eve 1999, he has consolidated power by bringing oligarchs to heel, banning any real opposition and turning Russia into an authoritarian state.

His most prolific critic, Alexei Navalny, died in an Arctic prison colony last month in mysterious circumstances. Other opponents are serving lengthy jail sentences or have fled into exile.