The internal politics of Latvia, never the likeliest topic at the bar of the Dog and Duck, made a surprise appearance on the agenda of the last General Election when David Cameron was accused of consorting with Latvian neo-Nazis in the European Parliament.

The fuss centred on an annual commemoration in the Baltic state of a battle between the country’s Waffen SS divisions and the Soviet Army in 1944. This remains a matter of burning controversy in Latvia, and if anyone felt under-served by the debate at the time, it’s the subject of a new play at the Royal Court’s Jerwood Theatre Upstairs by Aleksey Scherbak, a Russian-speaker based in Riga.

It would be easy to mock this subject as obscure, and you do need to be an anorak of sorts to make the effort. But it’s not without  interest. In the West we tend to forget that Stalin was just as horrific as Hitler for many persecuted Eastern Europeans, if not worse. It’s alarming to discover that a potentially murderous argument about this history is still raging today.

The problem is that Scherbak’s 90-minute drama, run without an interval, is a clunking affair. Desperately in need of humour, it  depends heavily on crude character stereotypes. The excellent ensemble cast, including Michael Nardone as a broad-minded Russian denounced as a traitor by his own people and Sam Kelly as a Russian-hating SS veteran, bring passion to their performances under Michael Longhurst’s direction. But the set-up of two neighbouring households, each equipped with a Bad Latvian/Russian and a Good Latvian/Russian, is far from subtle.

The discovery that the rabble-rousing apparatchiks from the two opposing sides are back-slapping mates on the sly stretches  credulity. And I simply didn’t believe the central conceit, that an ordinary Russian saying he understands the motives of the SS veterans would create a national scandal and knock every other story out of the headlines.

- Simon Edge