Leading article: A bout of judo diplomacy

The claim that Vladimir Putin was coming to London in a purely personal capacity to watch the Olympic judo was diplomatic artifice at its best. No doubt the Russian President was indeed keen to see his favourite sport. But his visit was also the latest in a long tradition of using sport as a cloak for politics.

Sure enough, Mr Putin was duly accompanied to the judo by David Cameron, after informal talks in Downing Street earlier in the day. Given that the Russian President has not been to Britain for nearly a decade – relations between the two countries were soured, first by tussles over exiled oligarch Boris Berezovsky and then by the poisoning of Alexander Litvinenko – such choreography is no small beer. And for all the, justifiable, concerns over Moscow policy – both domestic and foreign – signs of a rapprochement are still welcome.

Welcome, but far from easy. Although Mr Cameron claimed his priority is to talk trade, the main topic was, of course, Syria, and Russia's repeated refusal to back UN efforts to oust the Assad regime. There is, perhaps, a grain of hope that President Putin's being here at all indicates Moscow's growing discomfort at its isolation. But little more than a broad commitment to keep looking for a solution followed the talks. Meanwhile, the Russian criticism that there is no plan for what follows Bashar al-Assad's removal is not easily answered, and evidence of Syrian rebels executing pro-government fighters also leaves the straightforward moral arguments harder to make.

Nor is Syria the only thorny subject. Mr Putin's return to the presidency has been accompanied by alarming signs of repression. Demonstrations have been sharply put down and opposition figures harried – not least blogger Alexei Navalny, arrested on charges of embezzlement this week, and three members of Pussy Riot, on trial for singing an anti-Putin protest in a Moscow cathedral. For all that he was required to play the host, it can only be hoped that Mr Cameron registered suitable concern.

It would be a mistake to expect too much, too soon in Britain's relationship with Russia. But at least we are now talking.