Isfahan Calling, Old Red Lion, London

You never like to give too much away when there are thriller elements involved, but to disclose fully what happens in Philip de Gouveia's new play about a covert propaganda exercise in the desert would be as futile as it is virtually impossible: these guys may be calling in Isfahan but they're also shouting in Islington.

Making radio waves is one thing, but hot air waves are another, and it's never clear if De Gouveia's bunch of British journalists are themselves sure about what they are doing. The purpose of such Information Operations – Info Ops as they're known in the trade – is to influence decision-makers as well as audiences, and the growth in this kind of work around the global war on terrorism is considerable.

So it's a hot topic. In recent weeks, the BBC has launched a Farsi TV channel called BBC Persian, but Tehran has reportedly refused to allow the channel's journalists to work in Iran. De Gouveia's operators, led by the impetuous Roy of Paul McEwan, are joined by a new recruit, Zahra (Zahra Ahmadi), whose parents were forced into exile in the religious revolution of 1979. Not only that, she's been living in Romford, so there's not even an upside to being a refugee from an oppressive regime.

Kelly Wilkinson's production, neatly designed by Becky Gunstone to create a good sense of instant chaos among the wider political confusion, is enthusiastically acted without quite explaining the psychology of the campaign, so that when things happen – and the main thing that happens is a disastrously ill-judged broadcast in a period of heightened tension – they seem unduly melodramatic. And there's a shockingly violent climax that is as unexpected as it is hard to watch.

Philip de Gouveia is a freelance policy researcher with a good track record as a journalist with the BBC World Service, but he hasn't yet mastered the trick of communicating his ideas in dramatic language, so that discussion of propaganda tactics, for instance, comes across as a leaden, irony-free debate that leaves you gasping for air and light. The programme quotes Winston Churchill saying that "in wartime, truth is so precious she should always be attended by a bodyguard of lies", but it's hard to tell the difference in a play where assertion and counter-assertion are unrelated to either discernible motivation or theatrical revelation.

To 14 March (020-7837 7816)