'Stateless'; Tristan Bates Theatre, London

When the media already brings daily updates of radicalised Muslims fighting Western forces in war-torn lands, a drama about the toxic legacy of the Allied invasion of Afghanistan has to work all the harder to feel as relevant, and stave off well-worn clichés.

Stateless does that, and more. A remarkably mature play to have come out of Kali Theatre’s Talkback festival for new writers, its single set-piece pivots on the uncertain interplay between its two characters – Simon James Baillie’s Denny, an ex-squaddie once stationed in Helmand, now keeping watch at a secure psychiatric unit in Nottinghamshire, and Cat, a vulnerable out-of-towner, lost around these parts.

Cat, played by Shanaya Rafaat, appears at Denny’s guard-hut out of the rain like an alluring stranger. So Denny’s bumbling physical comedy in the opening scene gives way to sexual frisson. But Denny’s flirtation is not quite returned by Cat, and Rafaat is magnificent in cranking up the tension of an unnamed threat – a score to settle - until a pall of Pinteresque menace hangs over every exchange; violent confrontation may, or may not, stop short of detonation.

Just as Cat and Denny’s unknown connection keeps the audience guessing, so our sympathies switch between the two. Like all good tragedies, moral culpability appears complex, slippery: the aggressor is also the tragic victim, and the avenging victim might morph into the aggressor. The mess of war – its “collateral damage” – is shown enmeshed in the mess of personal grief.

Stateless is as cerebral as it is visceral: debates around personal responsibility in war are woven seamlessly with the drama’s emotional fulcrums. Rafaat and Baillie inhabit their roles completely. Add to that smooth direction from Trilby James and a pitch perfect script from Subika Anwar, and Stateless reveals itself to be a play of manifold emerging talents.