How could she? Why would she?

I don't suppose Private First Class Lynndie England ever expected to be famous. Suddenly, though, she is known around the world for taking part in what looks like a low-budget re-enactment of Salo, Pasolini's notorious film based on The 120 Days of Sodom by the Marquis de Sade. England was photographed in Abu Ghraib prison in Iraq leading a naked man on a dog leash, recalling a scene from the movie in which carefully selected victims are humiliated in this way by a bunch of Italian fascists. The episode is an acerbic commentary on the links between fascism and sexual sadism, which is not a comforting thought for President Bush this weekend.

I don't suppose Private First Class Lynndie England ever expected to be famous. Suddenly, though, she is known around the world for taking part in what looks like a low-budget re-enactment of Salo, Pasolini's notorious film based on The 120 Days of Sodom by the Marquis de Sade. England was photographed in Abu Ghraib prison in Iraq leading a naked man on a dog leash, recalling a scene from the movie in which carefully selected victims are humiliated in this way by a bunch of Italian fascists. The episode is an acerbic commentary on the links between fascism and sexual sadism, which is not a comforting thought for President Bush this weekend.

The images conjure up centuries of Orientalist prejudices, and I regret that Edward Said is no longer alive to decode them. He would have recognised instantly that race is central to these studied scenes of degradation, in which captives are forced to act out fantasies about the effeminate, sodomitical Arab male for the Western gaze. (Do any pictures exist of Iraqi women in US jails in Iraq? What new horrors are still to come?) We see here human beings stripped of individual identity, coerced into impersonating animals and simulating sex acts in a way that reveals their jailers' unacknowledged fears and desires. Like American negroes in the time of slavery, Iraqi men are deliberately dehumanised by such poses, placed on a level with animals whose sexual urges are, by definition, crude and bestial. I assume they make the perpetrators - many of them reservists, who never expected to serve overseas - feel potent at a time when US troops are being targeted by suicide bombers.

Other images from the prison bring to mind photographs of Nazi concentration camps. Others again - hooded men, spread-eagled against metal cages - mimic the vulnerability of animals in a vivisectionist's laboratory. How did England, whose job was to process new inmates at the jail, become involved in these pornographic scenes? She certainly seems to be enjoying herself as she points at the genitals of a line of naked men in another photograph. Did she imagine she could send it home to Virginia with a chirpy caption - "Hi folks, look what fun I've been having" - scrawled on the back? Western attitudes to the East have always consisted of an uneasy combination of desire and contempt, fear and envy, in which the Arab (and Turk, during the Ottoman Empire) can be inferior or terrifyingly superior but never equal.

The other thing we can say with certainty is that he - or she, if we include all those languorous 19th-century paintings of the Sultan's harem - is almost universally eroticised. The East stands in the Western imagination for exoticism and the forbidden, which is why it has drawn so many travellers from Europe. Think of Lord Byron, T E Lawrence, Lady Hester Stanhope and Lady Mary Wortley Montagu.

Think also of E M Hull, whose novel The Sheik, published in 1921, is perhaps the archetypal Orientalist fantasy. The wife of a Derbyshire pig farmer, Edith Maude Hull had never set foot in an Arab country, but the desert setting allowed her to create a fevered rape fantasy, in which an aristocratic Englishwoman is kidnapped and repeatedly ravished by Sheik Ali Ben Hassan. ("The flaming light of desire burning in his eyes turned her sick and faint ... 'Oh you brute! You brute!' she wailed, until his kisses silenced her.") That this is a device to legitimise erotic fantasies that could not have been staged in Buxton is confirmed by the ending, in which the Sheik is revealed to be (like Tarzan) the son of an English nobleman, played in the silent film version by Rudolph Valentino.

Such appropriations may seem harmless enough, but they add up to a collective imperialist fantasy that rightly makes the inhabitants of Arab countries resentful. Many of them already regarded the US and British forces in Iraq as a foreign occupation rather than a liberation, which is bad enough. But the pictures from Abu Ghraib, in which American power is explicitly represented as sexual humiliation, are just about the worst catastrophe for President Bush and every Western politician who has supported him over the war in Iraq.