At the height of the American bombing of Afghanistan last year, I went to see Maulana Sami-ul-Haq, one of the architects of the Taliban, while he was under house arrest in a grimy bedsit in Islamabad. After an impassioned speech denouncing America as the Great Satan, he served bottles of warm Pepsi.
From Riyadh, home of the only Harvey Nichols outside Britain, to Karachi, where McDonald's and Pizza Hut vie for business, you will find a combination of anti-western rhetoric and a fondness for western brand names. This has long been one of the great dichotomies of the Islamic world. But over the past few months, there has been a disturbing shift. These days, rather than Coca-Cola or Pepsi, the fundamentalist fizzy drink of choice is Zam Zam Cola, produced in Iran by the wonderfully named Foundation of the Dispossessed. Ten million bottles of the stuff have been exported to other Gulf states in the past four months. For not only have we failed to capture Osama Bin Laden or cripple al-Qaeda, but, in the crucial battle for hearts and minds, the western world is losing badly.
While during the cold war, vast resources were poured into beaming the Voice of America, Radio Free Europe and the BBC World Service behind the Iron Curtain, this time round western governments seem strangely reluctant to engage in the war of ideas. Thousands of elite soldiers in the SAS and America's Delta Force have been unleashed on the hunt for al-Qaeda leaders, and millions of pounds have been spent on bombs, planes, bribing warlords and reacting to each terrorist attack as it happens. More is to be spent on leafleting all 24 million homes in Britain with instructions on what to do in the event of a terrorist attack. But to try to win over the 280 million people who live in the Arab world, our main weapon is one man from Wimbledon.
In a large, high-ceilinged room at the Foreign Office, where the television is tuned to al-Jazeera and three clocks show the time in Washington, London and Abu Dhabi, sits the young (he's 29) diplomat whose task it is to spread the Blair message in Islamic countries.
Gerard Russell is director of the Islamic Media Unit, a special department set up last October after a meeting of Foreign Office mandarins in 10 Downing Street with Alastair Campbell. A fluent Arabic speaker, he has since given more than 200 interviews to Arabic television and newspapers and travelled to more than half the Arab world, a latter-day lone crusader in a sea of anti-western invective.
Russell may be an anonymous, slightly balding man in a pinstripe suit in London, but in the Middle East he is "Brother Gerard", recognised everywhere from petrol stations in the Sinai Desert to customs offices at Riyadh airport. When Tony Blair visited the unit, Russell was introduced to the Prime Minister as "the man more famous on al-Jazeera than you are".
He was shocked, upon returning from three years working on the peace process in east Jerusalem, to be called to No 10 and offered the job. He spent the following day doing practice interviews, and two days later was plunged into defending anything from Bush's policy towards Iraq to British policy in Northern Ireland, and answering questions such as "The Americans have plans to change the map of the region and what's the British reaction to this stupid plan?"
"It's very nerve-racking to go up on television in a foreign language, often in a hostile climate, but it hasn't been as hard as I thought it would be," he says. "Arab television is not Jeremy Paxman. Ninety per cent of people are very polite and let you finish your sentence . . . "
But not always: he shows me a video of a debate about Iraq on al-Jazeera where the other guest was Abdel-Bari Atwan, editor of Al-Quds newspaper, who refuses to let him complete a sentence and jabs his finger threateningly. It looks terrifying. Recently Russell addressed a meeting in Kuwait where a man burnt an American flag in the hall and shouted: "Death to Americans! Death to all British!" - then sat down in the front row.
As anyone who has taken a taxi or bought a newspaper in the Arab world in recent months can verify, one thing is common here. The widespread Muslim sympathy for the US in the immediate aftermath of 11 September has dissipated, as the Bush administration - and its closest allies, the Blair government - are perceived as making no effort to understand why people could hate the west so much that they would want to kill more than 3,000 innocent civilians, and themselves in the process. Instead, many Muslims are so angry that in places such as the Pakistani cities of Karachi and Quetta and the Hadhramaut wilds of Yemen, the people are not only boycotting American products and buying Osama Bin Laden kulfa sweets for their children, but also sheltering the terrorists.
"What I say to these people," explains Russell, "is that violence is not Islamic - more people have been killed in the name of Christianity over the centuries than in Islam. But the problem is, the moderates are not being heard. We need to encourage moderates to have the ability and courage to put their views across."
The most frustrating part of his work is the double standards: "People give very emotive enunciations of extreme views, on Arab television, but then in private are very logical and reasonable. That's one of the real problems. I know I'm getting through to people, but I can't expect anyone to admit it. In public, everyone has to be seen as on-message, as what they would call patriotic." He admits he has to be careful what he says, too.
"Presenters are always telling me it's impolite to speak ill of their leaders. For example, even saying 'Saddam' rather than 'President Saddam Hussein' is considered disrespectful."
Trying to convince people in the Islamic world to support the war on terrorism is not easy, given the conspiracy theories endemic in the region. "A lot of my job is demolishing myths," he says. "People are always saying to me: 'You're not still claiming 11 September was Osama Bin Laden. We Arabs could never organise such a sophisticated thing. We all know it was Ariel Sharon trying to give Muslims a bad name.'
"There are all sorts of bizarre ideas floating about the Middle East . . . When I talk about Iraq, they say: 'We know that Britain is the brains and America the muscle; it's really your plan, you're just pretending it's not.'
"Others say the war on terrorism is a kind of Christian crusade against Islamic countries. The problem is that there are so many misconceptions. I'm often asked how East Timor was liberated overnight and Palestine not. I say to them: 'Look, it wasn't: it took 24 years.' But apparently it wasn't covered; many Arabs had not heard of the issue. Of course if you think East Timor was liberated overnight and this was because it was Christian, then you'll think it's outrageous."
To try to reverse this, he mostly talks about Islam in the west. "Many in the Arab world don't realise we have two million Muslims in Britain," he says. "We took a group of Muslims to Saudi Arabia to meet members of the Saudi Shura [consultative council] and they were shocked - they did not realise we had Muslim MPs in Britain. In fact, they weren't even aware that a Muslim could emigrate to Britain and become a citizen. People are astonished to know we have 200,000 Iraqis in this country. Bizarrely, Tony Blair may have got more votes from Iraqis than Saddam."
With Arab channels showing a daily diet of violence on the West Bank, Russell believes it helps that he speaks Arabic with a Palestinian accent and is passionate about the Arab world. He began his love affair with the region while studying classics at Balliol College, Oxford, when he took a trip to Syria. "It feels like a place living side by side with history, whereas we've mostly left our history behind."
He insists: "To me, it's not proven that everyone in the Middle East hates Americans. You've got to remember, everyone watches American films, listens to American music, queues up for visas to go to America. There are a lot of contradictions out there."
But he admits that selling the west has become harder since Bush started to talk of attacking Iraq. "There's a lot of anger in the Middle East and it comes from many factors. The history of the region is very complex and not a very good basis for building modern democracy. Something Arabs often say to me is: 'You in Britain have had 1,000 years to build your democracy.' The Ottoman empire ruled large parts of the Arab world right up till 1917 and it was a closed empire. Foreigners were barely allowed in: even in 1850 or so, the British consul in Jerusalem had great difficulty getting in because the Ottomans didn't like the idea of foreigners in the Holy City."
Even so, one might think it unarguable that the region needs change. The recent Arab Human Development Report stated: "More than half of Arab women are illiterate . . . the quality of public institutions is low . . . one out of every five people lives on less than $2 a day." But Russell finds: "I have to be very careful when I talk about democracy that they understand this means power of the people, and not imposing western ways of life or undermining Arab identity."
The enormity of his task was made clear this month when a poll by YouGov for the Telegraph found that, even among British Muslims, one in five feels no loyalty to Britain; and more than half would not accept that the 11 September attack was carried out by Muslims. Even the battle of the fizzies is about to come to Europe: a Muslim entrepreneur in France is ready to launch Mecca Cola.
"We haven't really tackled the ideas issue effectively at all," admits a British intelligence official involved in the search for Bin Laden, "probably because it's difficult - but it has to be done. For if the corporate message still survives, it doesn't really matter whether Bin Laden is alive or dead."
Christina Lamb's book on Afghanistan, The Sewing Circles of Herat, is published by HarperCollins (£16.99)