The Resistible Rise of Arturo Ui, Lyric Hammersmith, London

This Arturo is all too resistible

Say what you like about Robert Mugabe, you can't fault his contribution to contemporary theatre. In 2006, the hoary old despot was compellingly portrayed in Fraser Grace's Breakfast with Mugabe for the RSC; now he's the subject of a new production of Brecht's dark gangster play, The Resistible Rise of Arturo Ui. It's recognition, if you like, of Comrade Bob's arrival in the premier league of world dictators.

Thanks to his stunning elevation, the Zimbabwean president can be uttered in the same breath as Adolf Hitler – about whom The Resistible Rise was originally written at the height of the Second World War. Brecht, in exile at the time, intended to create an unsubtle and angry allegory of the Führer's rise to power, complete with goose-stepping henchmen and plot-lines mirroring real-life events such as the Reichstag fire.

Today, his play is among epic theatre's most celebrated works, and considered to be a masterpiece of didatic political drama. The anti-hero Arturo Ui, a Chicago gangster loosely modelled on Al Capone, has been played by a proverbial Who's Who of big hitters – most notably Al Pacino and Antony Sher – and heralded as one of the greatest roles for a leading man outside of Shakespeare, whose Richard III he sometimes recalls.

All of which leads to Ui's latest incarnation at the Lyric in Hammersmith, created by the Zimbabwean actor Lucian Msamati, who also takes the lead role. The big idea, so to speak, is that Ui should represent Mugabe and a clutch of other African dictators rather than old Adolf.

On paper, it makes some sense: Brecht's original themes – corruption of the judiciary, violent suppression of the press, and what have you – are mirrored in modern sub-Saharan politics. Moving The Resistible Rise to Harare sounds like a cute idea. Then, alas, the curtain rises. There follows one of the most bafflingly inept displays of theatre you'll witness this side of the equator.

We open on a series of scenes that allegedly portray incidents from Ui's rise to power. Unfortunately, they're hopelessly garbled. One seems to involve cauliflowers; another, I think, sees a previously honest businessman coerced into selling a seaside harbour (incidentally, real-life Zimbabwe is landlocked). At some point, a couple of people get shot, with toy guns.

Throughout this mysterious sequence, it's quite impossible to understand what's going on, thanks to a combination of confused directing, wooden acting, and the difficulty (for this writer anyway) of understanding the cast's accented English. Msamati broods, stomps, is occasionally full of menace, and sometimes looks the part. But trying to unpick Brecht's plot from the tableaux he and his cast create is about as easy as snorkelling down a muddy Zambezi.

This isn't really acceptable in a professional production, and by the time things warm up – there's the occasional display of theatrical competence just before the interval – any hope of playing on the audience's emotions has disappeared into the empty air of an auditorium in which they've spent a good hour scratching their heads in bafflement.

The second act descends further into confusion. You've got a farcical portrayal of a Scrooge-like ghost. And a few more people get unconvincingly shot, or stabbed. It has the air of schoolboy production of Shakespeare: unconfident actors throwing away some of the greatest lines in the history of theatre.

Sloppiness extends to the programme, which treats us to a ludicrous grocer's apostrophe (a section on "African Dictator's") and an interview in which Msamati declares that we might, if we wish, see a bit of Gordon Brown, as well as Mugabe, Idi Amin, Mobutu and co, in his leading man. Well perhaps we might have; but somewhere along the line he's forgotten that, for an audience to see anything at all, you have to have successfully told them a story. His show is, if you'll forgive the expression, distinctly resistible.

To 15 March (0871 221 1729)