Russian president Vladimir Putin took power in 2000 with promises of recreating a strong, law-abiding state. The killing of Alexander Litvinenko, the former spy, and a spate of other assassinations suggest Mr Putin's Russia may well be strong - but it is far from being law-abiding.

Nobody has been charged over Mr Litvinenko's death. The range of possible suspects, including present and former security officers, businessmen and gangsters, is wide.