Just about the worst nightmare for any self-respecting spy is to be caught red-handed in the middle of an operation, and to expose the identities of colleagues in the bargain. Yet, over the past few weeks, this was precisely the fate of Russia's spies.

Two of Russia's intelligence service officers not only failed to assassinate their target in Britain, but also failed to dispose of their weapon, failed to escape detection and were also exposed to international ridicule when their implausible cover to be just some Russian salesmen in love with touring Britain's cathedrals was blown, and their true identities as military intelligence agents were exposed.