Whatever its immediate apparent outcome, the war on Iraq represents a catastrophic breakdown of the British and American imagination. We've utterly failed to comprehend the character of the people whose lands we have invaded, and for that we're likely to find ourselves paying a price beside which the body-count on both sides in the Iraqi conflict will seem trifling.

Passionate ideologues are incurious by nature and have no time for obstructive details. It's impossible to think of Paul Wolfowitz curling up for the evening with Edward Said's Orientalism, or the novels of Naguib Mahfouz, or Seven Pillars of Wisdom, or the letters of Gertrude Bell, or the recently published, knotty, often opaque, but useful book by Lawrence Rosen, The Culture of Islam, based on Rosen's anthropological fieldwork in Morocco, or Sayyid Qutb's Milestones. Yet these, and a dozen other titles, should have been required reading for anyone setting out on such an ambitious liberal-imperial project to inflict freedom and democracy by force on the Arab world. The single most important thing that Wolfowitz might have learned is that in Arabia, words like "self", "community," "brotherhood" and "nation" do not mean what he believes them to mean. When the deputy secretary of defence thinks of his own self, he - like me, and, probably, like you - envisages an interiorised, secret entity whose true workings are hidden from public view. Masks, roles, personae (like being deputy secretary for defence) mediate between this inner self and the other people with whom it comes into contact. The post-Enlightenment, post-Romantic self, with its autonomous subjective world, is a western construct, and quite different from the self as it is conceived in Islam. Muslims put an overwhelming stress on the idea of the individual as a social being. The self exists as the sum of its interactions with others. Rosen puts it like this: "The configuration of one's bonds of obligation define who a person is . . . the self is not an artefact of interior construction but an unavoidably public act."

Broadly speaking, who you are is: who you know, who depends on you, and to whom you owe allegiance - a visible web of relationships that can be mapped and enumerated. Just as the person is public, so is the public personal. We're dealing here with a world in which a commitment to, say, Palestine, or to the people of Iraq, can be a defining constituent of the self in a way that westerners don't easily understand. The recent demonstrations against the US and Britain on the streets of Cairo, Amman, Sanaa and Islamabad may look deceptively like their counterparts in Athens, Hamburg, London and New York, but their content is importantly different. What they register is not the vicarious outrage of the anti-war protests in the west but a sense of intense personal injury and affront, a violation of the self. Next time, look closely at the faces on the screen: if their expressions appear to be those of people seen in the act of being raped, or stabbed, that is perhaps closer than we can imagine to how they actually feel.

The idea of the body is central here. On the website of Khilafah.com, a London-based magazine, Yusuf Patel writes: "The Islamic Ummah is manifesting her deep feeling for a part of her body, which is in the process of being severed." It would be a great mistake to read this as mere metaphor or rhetorical flourish. Ummah is sometimes defined as the community, sometimes the nation, sometimes the body of Muslim believers around the globe, and it has a physical reality, without parallel in any other religion, that is nowhere better expressed than in the five daily times of prayer.

The observant believer turns to the Ka'aba in Mecca, which houses the great black meteorite said to be the remnant of the shrine given to Abraham by the angel Gabreel, and prostrates himself before Allah at Shorooq (sunrise), Zuhr (noon), Asr (mid-afternoon), Maghreb (sunset) and Isha (night). These times are calculated to the nearest minute, according to the believer's longitude and latitude, with the same astronomical precision required for sextant-navigation. (The crescent moon is the symbol of Islam for good reason: the Islamic calendar, with its dates for events like the Haj and Ramadan, is lunar, not solar.) Prayer times are published in local newspapers and can be found online, and for believers far from the nearest mosque, a $25 Azan clock can be programmed to do the job of the muezzin. So, as the world turns, the entire Ummah goes down on its knees in a never-ending wave of synchronised prayer, and the believers can be seen as the moving parts of a universal Islamic chronometer.

In prayer, the self and its appetites are surrendered to God, in imitation of the prophet Mohammed, the "slave of Allah". There are strict instructions as to what to do with the body on these occasions. Each prayer-time should be preceded by ritual ablutions. Then, for the act of prostration, and the declaration of "Allahu Akbar" (God is great), the knees must touch the ground before the hands, the fingers and toes must point toward Mecca, and the fingers must not be separated. Forehead, nose, both hands, both knees, and the underside of all the toes must be in contact with the ground. The body of the individual believer, identical in its posture to the bodies of all other believers, becomes one with the Ummah, the body of the Islamic community on earth. The abdication of self five times a day, in the company of the faithful millions, is a stern reminder that "self-sufficient" is one of the essential and exclusive attributes of Allah, mentioned many times in the Koran. Human beings exist only in their dependency on each other and on their god.

The physical character of this prayer is unique to Islam. Jewry and Christendom have nothing like it. The Ummah, a body literally made up of bodies, has a corporeal substance that is in dramatic contrast to the airy, arbitrary, dissolving and reconstituting nations of Arabia. To see the invasion of Iraq as a brutal assault on the Ummah, and therefore on one's own person, is not the far-fetched thought in the Islamic world that it would be in the west.

For weeks the Jordan Times, like every other newspaper in the region, carried front-page colour pictures of civilians killed or wounded in Operation Iraqi Freedom. Government censorship being what it is, these photographs could afford to be more eloquent and candid than the stories printed beneath them. On April 2, the picture was of an Iraqi father in a dusty grey jellaba, arms spread wide, screaming at the sky in grief, while at his feet, in a single barewood open coffin, lay huddled the three small, bloodied bodies of his children. His rage and despair can be seen exactly mirrored in the faces of Egyptian demonstrators in Tahrir Square, as the Ummah bewails the injuries inflicted on it by the western invaders. Geographical distance from the site of the invasion hardly seems to dull the impact of this bodily assault.

It's no wonder the call of the Ummah effortlessly transcends the flimsy national boundaries of the Middle East - those lines of colonial convenience, drawn in the sand by the British and the French 80 years ago. Wolfowitz repeatedly promises to "respect the territorial integrity" of Iraq. But integrity is precisely what Iraq's arbitrary borders have always lacked: one might as well talk about respecting the integrity of a chainsaw, a pair of trousers and a blancmange.

When the British cobbled together Iraq out of three provinces of the collapsed Ottoman empire, they were deliberately fractionalising and diluting two of the three main demographic groups. It made good colonial sense to split up the ever-troublesome Kurds (Sunni Muslims, but not Arabs) between Syria, Turkey, Persia, and Iraq. Equally, the Shias had to be prevented from dominating the new state. In her letters home, Gertrude Bell, an archaeologist and official of the British administration in Baghdad after the first world war, described the Shias as, variously, "grimly devout", "violent and intractable", "extremist", "fanatical and conservative". By contrast, the Baghdad Sunnis were seen as generally docile, forward-looking and pro-British. A representative democracy was out of the question, because the majority Shias would promptly hijack it. Bell wrote: "I don't for a moment doubt that the final authority must be in the hands of the Sunnis, in spite of their numerical inferiority, otherwise you'll have a mujtahid-run, theocratic state, which is the very devil." (Wolfowitz, please note. Out of the lawless turmoil of liberated Iraq there emerged one image of placid civil order: a photo, taken last week and published in the New York Times, showing some 700 Basra Shias seated in neatly serried rows outside their damaged mosque, listening to a sermon. This in a city otherwise given over to riot, looting and murder. The contrast between the power of the occupiers and the power of the ayatollahs could not have been more forcefully stated.)

Bell and her colleagues sent for Faisal - son of the emir of Mecca - who had already had a go at being king of Syria before the French deposed him. As a member of the Hashemite family, direct descendants of the prophet, Faisal, though a Sunni, was acceptable to the Shias. So the perils of democracy were neatly circumvented.

Bell again: "Lord! They do talk tosh. One of the subjects that even the best of [the Arabs] are fond of expatiating upon is the crying need for democracy in Iraq - al damokratiyah, you find it on every page. I let them run on, knowing full well that Faisal intends to be king in fact, not merely in name, and he is quite right."

From the start, the unwieldy assemblage of Iraq needed not a government but a ruler. When monarchy failed, tyranny of a peculiarly Middle Eastern kind took over. Rosen interestingly asserts that the idea of "state", in the western sense of a complex machinery of government independent of the person of the ruler, barely exists in the Arab world, because an entity as abstract and impersonal as a state cannot be credited with those "bonds of obligation" that define and constitute the Islamic self. This is borne out by fundamentalist websites that warn their followers not to vote in western elections for fear of committing the sin of shirk, or blasphemy: to show allegiance to a secular state, instead of to the Ummah and to Allah, is to worship a false god. The typical Arab ruler is likely to echo Louis XIV: the state, such as it is, is him - a warlord-like figure on a grand scale, with an army and a secret police at his disposal, like Nasser, Hafez al-Assad, King Saud, or Saddam Hussein. For the individual strong man is compatible with strict Islamist teaching in a way that a strong state is definitely not.

In the case of Iraq, arrogant colonial mapmaking happened to conspire with Islamic tradition to create a state that would permanently tremble on the verge of anarchy, or at least of violent partition into a Kurdistan to the north, a Shi'ite theocracy to the south, and a Sunni-led secular statelet in the middle with Baghdad as its capital. That Iraq still conforms - just - to its 1921 borders is a tribute to the extraordinary power and brutality of Saddam. Yet Wolfowitz has singled out this state-that-never-should-have-been for his breathtakingly bold experiment in enforced American-style democracy. On April 6 he went the rounds of the Sunday-morning talk-shows to "warn" the nation that it might take "more than six months" to get Iraqi democracy up and running. He should be so lucky. What seems to be happening now is that, as American troops take full possession of Iraq, they are beginning to find out - in Baghdad, Ur, Mosul - that the country they invaded has effectively ceased to exist.

Beware of the Ummah. Never has the body of believers been so vitalised by its own pain and rage. The attacks on Gaza and the West Bank by Israeli planes and tanks, the invasion of Afghanistan and the invasion of Iraq are seen as three interlinked fronts of the same unholy project. Each magnifies and clarifies the others. Pictures of American troops in Bahgdad are eerily identical to those of Sharon's army in Gaza City, right down to the black hoods and white plastic cuffs used by both Americans and Israelis on their prisoners. Likewise, the bloody corpse of a Palestinian child appears in the same front-page space on Wednesday that was on Tuesday occupied by the bloody corpse of her Iraqi cousin.

Just as the American invasions of Afghanistan and Iraq gave the Sharon regime cover for fresh reprisals against the Palestinians, so they have given the Palestinians themselves a global context for their struggle. The image of overwhelming western military force bearing down on an oppressed Muslim people, once local and particular, is now general. Two weeks ago, at a massive demonstration in Alexandria, the crowd moved through the streets chanting: "America and Israel are one enemy, Iraq and Palestine, one cause."

That such demonstrations are happening at all, in places where political demonstrations are normally instantly disbanded by armed riot-police, is a measure of how even the repressive tyrants of the Middle East are having to bend to the fury of their people. Hosni Mubarak, who presides over a country that is constantly threatening to erupt in an Islamist revolution, warned that the American action in Iraq would "create a hundred Bin Ladens". Since the invasion began, Mubarak has had to tolerate criticism of his regime in the Egyptian newspaper Al-Ahram, which is a little like Khrushchev taking criticism from Pravda. Similarly, King Abdullah has been seen on Jordanian national television, defending his fence-sitting policy against a barrage of questions that showed scant respect for his regal person. All these might, of course, be seen as welcome signs of "liberalisation", although it's doubtful if Wolfowitz ever meant to liberate the Middle East in order to bring the rights of free assembly and expression to millions of enraged theocrats.

On April 7, Fahed Fanek wrote in the usually mild-mannered Jordan Times: "What can the world do to confront the overwhelming superiority of the US air-force? Nothing more than face up to it with hatred of America, its policies and the Bush administration. It is possible that the weapon of hatred will prove more effective and more enduring than that of the American air force."

Don't mistake the tone here. Fanek is no advocate of the hatred he describes. Yet hatred of America is becoming so deeply ingrained in the essential character of Arabia that even America's friends in the region, like Fanek, are having to write of it as a governing fact of Arab life, as incurable as weather.

For the first three weeks of Operation Iraqi Freedom there was extraordinary unanimity in the way the story was handled in English-language newspapers across the region, as by Islamist websites around the world. Every downed American helicopter and captured American tank was a trophy to be gloated over. Every Iraqi casualty was a brother or sister to be mourned. Every day when Allied progress was apparently slowed or halted was celebrated as a cause for pan-Arab, pan-Islamic pride. "Muslims of Iraq greet the Crusaders with bullets not flowers" was a representative headline. Government-controlled newspapers, usually regarded by the Islamists as craven lackeys of America's puppet-rulers in the region, were very nearly of one voice with the hardline jihadist websites. One such site, run by al-Muhajiroun ("The Emigrants") in London, has a grisly photo-feature under the jeering title of "BBC: 'We Are Winning'". The pictures that follow are close-ups of dead and horribly wounded Allied troops, weeping Allied PoWs, and wrecked Allied military hardware, interleaved with sarcastic quotations from members of the Bush administration, like "This will be a campaign unlike any other in history", "There's pockets of resistance, but we're making good progress", and "It is a breathtaking sight to see it." Yet what is most striking is that al-Muhajiroun, followers of the one-eyed, hook-handed Sheikh Omar Bakri Muhammad, are now only slightly out of step with the mainstream Arab press, where most of the photographs made their first appearance, and were meant to carry the same message.

The invasion seems, ominously, to have moved Osama bin Laden from the margin to the centre. It is his words that keep surfacing - like "crusaders", which first came to wide public notice in "Jihad Against Jews and Crusaders", the freelance fatwa issued by Bin Laden in February 1998. There he wrote: "The Arabian peninsula has never - since Allah made it flat, created its desert, and encircled it with seas - been stormed by any forces like the crusader armies spreading in it like locusts, eating its riches and wiping out its plantations. All this is happening at a time in which nations are attacking Muslims like people fighting over a plate of food."

Seven years after the first Gulf war, this sounded overblown and out of date. Now, with an American military occupation pitched in Iraq for an indefinite period, the extravagant phrasing has taken on an unexpected kind of realism. So too with "crusaders". Then, in the obsessively memorious way of Arabia, it quaintly harked back 900 years; now it conjures the fundamentalist Christian zealotry of the Bush administration and its religiose war on "evil". And calling the invading forces "crusaders" serves another function: it dissolves distinctions of nationality and creates an anti-Ummah, a malign global body of unbelievers, with all the unanimity of purpose and conviction attributed to the Ummah itself.

After September 2001, an immense quantity of effort was put into the discovery, or creation, of the elusive and precious link between the Iraqi regime and Bin Laden's al-Qaida organisation - a task that defeated all the best American and British alchemists. It took invasion to bring the link into being. Now it's there in full view, as sturdy a piece of ironmongery as anyone could wish for, with "Made in America" stamped all over it. In the last few weeks, Bin Laden's cause has acquired a degree of legitimacy that would have been inconceivable a year ago. Our dangerous new world is one in which seeming rhetorical embellishments are fast morphing into statements of literal fact, and Mubarak's forecast of a hundred Bin Ladens could turn out to be a serious underestimate.

Beware triumphalism. On the day that Allied troops crossed the border from Kuwait into Iraq, a CNN reporter named Walter Rodgers was to be seen "embedded" in an Abrams tank. Rodgers is what Americans call "an older man", but aboard the tank, in the company of boys from the "Seventh Cav.", he appeared to have regained his lost youth, in all its callow swagger and bounce. Prattling exultantly about the deadly potency of his big 120mm gun, Rodgers rode off into the desert, a gravel-voiced, ash-haired Tom Sawyer on a romantic teenage escapade.

His reporting gave deep offence. The next day, a CNN correspondent based in Qatar told how a Palestinian friend of hers in Beirut had expressed alarm at the "gee whiz" style of the network's coverage of the invasion - clearly a reference to Rodgers. Once, jingoistic news broadcasts were received only by the domestic audiences whose morale they were designed to boost. Now, when Walter Rodgers growls into the mike that he and his boys are going to "bite a chunk off Baghdad", he can be heard and seen by Islamists around the world as the living embodiment of America in her war of conquest and revenge.

On September 11 2001, Americans were sickened by the image of Palestinians dancing in a Jerusalem street, in demented jubilation at the collapse of the World Trade Center. Beamed from one world into the homes of another, the cheering celebrants appeared subhuman - not people but a whooping pack of Tasmanian devils at the kill. There have been moments in the American cable-TV coverage of the Iraq invasion when that image has come uncomfortably to mind. "Sickened" is a fair description of the tone of the English-language Arab press as it has contemplated both the war itself and America's apparent gusto for it. So familiar a revulsion ought, surely, to command recognition from us, but America has treated Arab opinion with haughty indifference, dismissing it - when it condescends to notice it at all - as standard-issue "anti-Americanism", that reflexive grouchiness which tends to affect anyone unlucky enough not to carry a US passport.

On television, the Iraqis themselves have been relentlessly feminised and infantilised, exactly along the lines described in Said's Orientalism . They are the Little People: all heart and no head, creatures of impulse and whim, not yet grown-up enough to make rational decisions on their own behalf. Surveying a scene of bloody chaos in Mosul, with gunshots exchanged between gangs of looters, the Fox News reporter indulgently observed that all this was only to be expected, because "their emotions have been so bottled-up, after 30 years of dictatorship". Ah, yes.

Children need fathers, and the person appointed by the US (the Pentagon, to be precise) to act in loco parentis to the unruly young Iraqis is someone perfectly typecast to administer the smack of firm paternal government. The retired general Jay Garner is a defence missile contractor ("arms dealer" in the Arab press) and close associate of Wolfowitz, defence secretary Donald Rumsfeld and vice-president Dick Cheney, whose best-known political avowal was his signature of the "Flag and General Officers' Statement on Palestinian Violence" put out by the Jewish Institute for National Security Affairs in October 2000: "We, the undersigned, believe that during the current upheavals in Israel, the Israel Defence Forces have exercised remarkable restraint in the face of lethal violence orchestrated by the leadership of a Palestinian Authority that deliberately pushes civilians and young people to the front lines.

"We are appalled by the Palestinian political and military leadership that teaches children the mechanics of war while filling their heads with hate. . ."

Unsurprisingly, the Jewish weekly Forward welcomed the news of Garner's appointment with the headline "Pro-Israel General Will Oversee Reconstruction of Postwar Iraq". Unsurprisingly, the news incensed the Arab world - as, no doubt, it was calculated to do, for the selection of Garner was nakedly triumphalist and entirely in keeping with the Bush administration's policy of teaching the Middle East a humiliating lesson.

Here's another metaphor that could turn literal. Last September, Amr Moussa, secretary-general of the Arab League, said if the United States invaded Iraq it would "open the gates of hell". Florid arabesque or fair warning? We shall soon find out.