Marat/Sade, Royal Shakespeare Theatre, Stratford-upon-Avon

To mark its 50th birthday, the RSC is revisiting its past glories. These don't come more celebrated than Peter Brook's 1964 staging of the Marat/Sade. His world-famous production jostled the in-yer-face sensationalism of Artaud and the cool, distancing devices of Brecht and created a theatrical revolution in the deeply unnerving way it handled this dialectical drama by Peter Weiss about the failure of the French Revolution.

Anthony Neilson's intrepid new staging wisely refuses to go down the route of reverential re-creation and it's vastly better than the most recent National Theatre version - a production so tame it kept making me muse on the odd affinities between Marat/Sade and Alan Bennett's Forty Years On (for amateur dramatics in a madhouse, read ditto in a boys' public school).

The fundamental change Neilson has made is to bring the proceedings up to date. We are still ostensibly in 1808 watching the inmates of the Charenton Asylum perform a play, scripted and overseen by the Marquis de Sade, about the assassination of Marat in 1793. Except that here 1808 looks a lot like now. The supposedly liberal Governor controls his charges by threatening them with texts from a smartphone. Kitted out like a contemporary terrorist, Charlotte Corday (Imogen Doel) tortures a compliant Sade with a Taser device and poses thumbs-up afterwards like Lynndie England in Abu Ghraib. Arsher Ali's self-consciously earnest Marat is a laptop proto-totalitarian; Jasper Britton's archly provocative Sade is a kinky, cross-dressing chameleon and voluptuary of alternative selves.

This temporal shift certainly throws up strong images that enliven the ideological debate between the two title characters. Sade’s advocacy of unbridled individualism is tellingly travestied in the way the inmates keep turning into a bunch of masturbatory loners hooked on the atrocity pics they've captured on their mobiles. The North African lilt of Khyam Allami's music and the costuming bring a smack of the Arab Spring to Marat's proselytising for revolution. The trouble, though, is that any production of Marat/Sade needs to convince you that the situation could get dangerously out of hand. But the "mad" acting here, through strenuous, signally fails to unnerve. When the compulsive erotomane gives chase to Corday, it's more Benny Hill than Bruegel.

There are some powerful performances - in particular that of Lisa Hammond who, as the Herald, narrates with a subversively sardonic chirpiness from her motorised wheelchair. But the attempts at disconcerting audience participation are feeble. Despite the dildos and the excrement and the pelted popcorn, I’ve felt less safe from the performers at many a pantomime.

To 5 November (0844 800 1110)