Alternately squirming and yawning my way through Peter Sellars's production of Idomeneo at Glyndebourne, I remembered something Clive James once said about an earlier staging of the Mozart opera. My compatriot's quip was provoked by Gotz Friedrich's production at Covent Garden during the 1970s: the East German ideologue coloured Idomeneo grey - like the carious, sodden concrete of the Berlin Wall - and presented Mozart's family tragedy as a Brechtian diatribe about the overthrow of patriarchy and the upsurgence of demos (embodied by a marauding sea monster). Directing opera, James remarked, was what the Germans now did instead of invading Poland. A generation later, the observation has to be modified to fit the ugly trivialisation of Idomeneo that Sellars has been imported from California to perpetrate: directing opera is what the Americans do at the same time as they're invading Iraq.
In Friedrich's case, the theatre was at least a peaceable alternative to conquest. With Sellars, it is warfare by other means. He naturally imagines that his production is a protest against the military bravado of the Bush regime. Idomeneo, the monarch compromised by the need to sacrifice his own son, is made to resemble the US president, bureaucratically besuited, with a patriotic pin in his lapel. The foreign princess Ilia is a captive Muslim, whose slaughtered brothers slump on the floor in zip-fastened body bags; her captive countrymen are manacled internees at Guantanamo Bay, menaced by supposedly Cretan marines in olive-drab camouflage gear. It all looks like a political cartoon, though it lacks the humour. For reasons I would rather not know about, this blundering farrago takes place somewhere in the nether regions of a large red lady: Anish Kapoor, pretentiously billed as "artist" rather than production designer, locates the first act between the chubby ogre's legs, and later opens a gash in the floor which, as greedy as a dentated vagina, gobbles up the unwary.
Whenever Mozart inconveniently contradicts this radical rant, the opera's text is unscrupulously revised. Sellars treats the projected titles as his own brash entitlement to authority and, rather than accurately translate the libretto, he unfurls anachronistic slogans across the proscenium. Thus the chorus sings about the terror of "a universe without god", and Arbace, Idomeneo's spin-doctor, cynically tells his employer that "If you can't take it, stay away".
The singers look baffled, and - with the exception of Magdalena Kozena as Idamante, the son Idomeneo is required to slay - they sound wretched. I can only assume that Simon Rattle, conducting the Orchestra of the Age of Enlightenment, has ears where his eyes should be. Why bother engaging a period band to reproduce the timbres the score had when first performed in Munich in 1781, if you insist that it's all taking place in Washington, DC in 2003?
Having scuttled Idomeneo, Sellars then found time to sabotage John Adams's El Nino, a Nativity oratorio unseasonably performed at the Barbican late in June. Another pitiable collection of singers was drilled in the semaphoric gestures that Sellars uses to externalise emotion: hands clasped in the air signal prayer, a palm slapped against the brow indicates mental distress, and a fist thumping the chest - geddit? - announces heartfelt sincerity.
As if this ritualised posturing were not enough of a distraction, Sellars upstaged Adams's score by projecting a film on to the back wall. A Chicano Holy Family flees Herod's helicopters by driving south from Los Angeles towards the Mexican border; the Annunciation occurs in the laundry room of a drab apartment block, and a cop has a religious vision while chomping on a greasy hamburger at a roadside diner. At the end of the performance, which was conducted by the composer, Sellars bustled on to the platform and orchestrated the applause, telling the orchestra when to stand. Having rewritten Mozart, does he imagine himself to be the auteur of El Nino?
Sellars grandiosely officiates as professor of world arts and cultures at the University of California, Los Angeles. But despite his global pretensions, he is hardly a universal man. This homesick provincial transforms the world's plethora of cultures into replicas of the US: he has set The Magic Flute under a Los Angeles freeway, The Marriage of Figaro in the Trump Tower, Don Giovanni in Spanish Harlem, Tannhauser at a Chicago airport, and Pelleas et Melisande in a cantilevered mansion on the crumbly seafront in Malibu, California. His work - as batteringly crude as the tanks that rolled into Baghdad, as crassly standardised as the burger joints that will no doubt soon open there - is a morbid symptom of the US imperialism he claims to deplore.
Peter Sellars gives the BBC Proms Lecture on "The Culture of Democracy" at the Victoria and Albert Museum on 3 August. His production of Handel's Theodora is at Glyndebourne from 10-31 August