There is little doubt that the co-ordinated online attack targeted at a Georgian blogger last week – which had the effect of temporarily bringing down Facebook, Twitter and LiveJournal – was politically motivated. Rather more uncertainty, though, surrounds the contention of the blogger in question that the Kremlin was responsible for the disruption.

We need to be cautious of taking this accusation at face value. No evidence of official Russian involvement in this attack has been uncovered.

Yet this is not the first time a state has been accused of engaging in "cyber warfare". China was accused of hacking into the servers of Western governments in 2007. North Korea is believed to have attacked South Korean computers earlier this year. And Russia itself...