They say it changed the world for ever. But how?

Life will never be the same again, some said as the twin towers fell. They were right. As the terror attacks continue, experts describe how the events of September 2001 still affect us all

US

US

By Rupert Cornwell

The priorities of US politics were transformed by 9/11. Healthcare, welfare, education and the economy remain the core issues separating Republicans from Democrats, but a proven competence on national security issues is now an essential qualification for the White House, as never before.

The Democratic convention in Boston was so wrapped in the flag that it might have been organised by the American Foreign Legion.

John Kerry supported the invasion of Iraq, the wisdom of which many Americans now doubt, but his military service qualifies Mr Kerry to take issue on it with President Bush.

In terms of national security, the changes have been legislative and practical, but above all psychological. In the wake of 9/11, the Bush administration urged - and Congress passed with only the scantest of debates - the Patriot Act, giving the federal government sweeping new powers to conduct surveillance and detain suspects, and breaking down some of the barriers between the security agencies.

People who had been charged with no offence could be held for months with no court hearings.

Belatedly, however, the Supreme Court has moved to curb the government's powers, insisting that suspects - even those held at Guantanamo Bay - must have legal representation.

America's mindset has changed, especially in the East Coast cities presumed to be at the top of al-Qa'ida's target list. Airport security is stifling.

A colour-coded threat-alert system has been introduced, but instead of clarifying the danger it has only added to the confusion.

Official warnings are invariably not accompanied by specifics.

Unlike citizens of many European countries, hardened by decades of domestic and international terrorism, Americans have yet to accept terrorism as something they just have to live with.

BRITAIN

By John Rentoul

The effects of 9/11 took a while to be felt in Britain. Immediate fears of an American over-reaction faded, and it was widely assumed that Tony Blair was indulging in idealistic hyperbole in his speech to the Labour Party conference three weeks later when he sought to use the sense of global solidarity engendered by 9/11 to try to solve all the world's problems.

He was naive, but not wrong in his assessment of the power of the event to alter the course of world history. Despite a keen understanding that "the kaleidoscope had been shaken", he suffered more than most world leaders from the whiplash.

The road to war in Iraq, and the even rockier road from it, have utterly dominated his second term. Far from using the power of the US to solve problems, he has ended up trying and mostly failing to stop George Bush from making things worse.

While most people took his promise to stand "shoulder to shoulder" with the American people as a condolence, the practical implications of which would be conditional on American restraint, he saw it as a geopolitical imperative. The contours of British politics are being reshaped as a result, with Labour voters broadly supportive of the invasion of Iraq, Liberal Democrats opposed and Conservatives evenly divided. The lasting effect on foreign policy has been to focus on "rogue states" and counter-terrorism.

But it took time, and the failure of intelligence on Saddam' Husseins armoury, for public spending on the secret services to be increased. The James Bonds of the future will be recruited from the streets of Bradford rather than the smoking chairs of the Travellers Club.

THE MIDDLE EAST

By Said Aburish

Those Muslim zealots who attacked and humiliated America inadvertently created a new Arab-West relationship. The leaders of Saudi Arabia, Egypt, Jordan and the Palestinian Authority used to be the West's deputy sheriffs in the region.

They followed relatively moderate policies towards Israel and guaranteed the flow of oil at a reasonable price.

Fourteen of the 19 hijackers on 11 September were Saudi Arabs. Saudi Arabia's inability to reconcile an Islamic fundamentalist policy at home and a pro-West one elsewhere was exposed. The House of Saud reverted to its religious origins even though Washington advocated political reforms instead.

President Mubarak of Egypt's inability to mediate between the Palestinians and Israel made him redundant. Washington responded by reducing Egypt's economic aid. King Abdallah of Jordan is caught between Palestinians who want to overthrow him and Muslim fundamentalists who want him to side with them against the US. Abdallah cannot survive without US economic and political support. Both have disappeared.

Yasser Arafat believes America is the only power that can deliver an Arab-Israeli peace agreement. Until recently America felt the same about him. But his people have turned against him. Nowadays America ignores him and treats him with disdain.

America, justifiably angry, no longer feels any obligation to support its old deputies, because they are incompetent. But the Arab people could have told them that decades ago.

Said Aburish is author of 11 books on Middle East affairs, including biographies of Saddam Hussein and Nasser

WORLD ECONOMY

By Hamish McRae

The travel and tourism industries lost out after 9/11. The rise in the oil price is as much an effect of rising demand, particularly from China, as of terrorist-related concerns about supply.

Global business in general has suffered and international direct investment has been falling since 9/11, as companies worry about global risk. All that you might expect. More surprising has been the relative success of the US economy.

In the summer of 2001 the US was heading towards recession. The attacks ought to have pushed it deeper into the hole. But cuts in interest rates and a surge in public spending boosted the economy enough for the US to start its slightly uneven recovery - though at the price of even greater fiscal and current account deficits that the country has to live with now. Continental Europe, by contrast, went on down, depressed by weak growth in international trade. Only this year has it begun to recover.

But the US may suffer more in the longer term. It has become less of a magnet for foreign talent. The difficulty of getting US visas has pushed bright students to the UK, Canada and Australia instead. In this respect the UK has been a huge beneficiary; no one predicted that. In the professional job market much the same has happened, with international companies choosing to expand in the UK rather than the US.

Eventually the US will start to look outward again. Until it does, that will be the lasting damage of 9/11 to its economy.

INTELLIGENCE

By Phillip Knightley

Spy-masters justify their enormously expensive existence by telling their political bosses that they can identify any monster lurking out there and give timely warning before it stirs. This promise, the foundation of their work,looked fragile after 9/11.

The theory is that a network of spies and agents picks up the gossip, rumours, facts and theories and relays them to headquarters for analysis. This process is called human intelligence gathering, or "humint". Signals intelligence, or "sigint", uses enormous listening posts at Cheltenham and Maryland, in the US, to eavesdrop on everyone and everything.

In 2001, Maryland intercepted two messages indicating al-Qa'ida was planning a spectacular terrorist attack within the US on 11 September. But the flow of material was so great that no one got round to reading these intercepts until after the twin towers had fallen.

Now sigint is trying to identify important intercepts more quickly. This is a slow, technologically tricky process. Changes in humint procedures are taking even longer to implement. After concentrating on the Soviet Union for years, MI6 and the CIA have found they cannot switch to counter-terrorism overnight.

They have lots of Russian-speaking officers but few Arabic speakers. It takes at least five years to recruit a new network of agents and to test their loyalty and information. Hence the fiasco over the non-existent weapons of mass destruction. The shadow 9/11 cast over the intelligence services remains.

MILITARY

By Robert Fox

The attacks confronted the military with a new threat and a new piece of jargon: global network terrorism. They had an effect beyond the immediate destruction of lives and property, because of al-Qa'ida's mastery of the new means of propaganda from the internet to satellite television. The essence of al-Qa'ida's power is that it is not dependent on the power of states or alliances of states. Striking Afghanistan was to hit a blob of mercury with a hammer; the movement has broken, divided, multiplied and gathered new strength and capability.Military thinkers have had to rewrite the tactical lexicon. Now the accent is on gathering intelligence and being able to respond rapidly before the target vanishes. The most high-profile "time-sensitive target" to date was Bin Laden himself when he appeared in the Tora Bora mountain complex at the end of 2001. More than 70 SAS, US and Canadian forces flogged through the mountains - a colossal waste of resources. It was too late. He had moved on, to fight (or inspire the fight) another day. Sophisticated military machines are restricted by the time they can endure in the field before they lose their edge, fitness and capability. The occupation of Iraq is proving exhausting. Bin Laden and his supporters believe time is on their side: they can attack and then wait, for they are playing for eternity.

Robert Fox is a broadcaster and military historian

TERROR

By Paul Lashmar

Security forces across the world have had to bury national rivalries and work together to fight al-Qa'ida, and in fairness, they have done a remarkable job.

It is estimated that more than 100 planned terrorist attacks have been prevented since 9/11, many in the US and Britain.

Almost two-thirds of al-Qa'ida's known leaders have been captured or killed and more than $200m (£111m) belonging to terrorist accounts has been seized. But new heads grow on the Hydra when one is cut off. And it would seem, from various videos broadcast on Arabic television stations, that Bin Laden is alive, supported by his deputy, Dr Ayman al-Zawahiri.

Last month, an American expert estimated that about 70,000 trained terrorists remain at large around the world. Daniel Benjamin, former counter-terrorism adviser to President Clinton, said only about 3,500 al-Qa'ida or other Muslim terrorists had been "taken out" in the last three years.

Experts on al-Qa'ida believe that Britain is the terror group's prime target. Since 9/11, MI5 has monitored those it suspects of close links with al-Qa'ida, most of north African birth and believed to number around 30. In addition there is a concentric ring of between 300 and 600 supporters and active sympathisers. A worry for MI5, reflected by a spate of arrests, is a small but growing number of British-born Muslims becoming al-Qa'ida supporters.

The internet has become central to linking groups across the world. Gabriel Weimann, a senior fellow of the United States Institute of Peace, has been monitoring terrorist websites for seven years. "When we started, there were only 12 sites. Now there are more than 4,000. It's a virtual training camp."

USA

September 11 2001

World Trade Center - 2,752 deaths

Pentagon - 169 deaths

Flight 93 - 44 deaths

Russia

1 September 2004

Terrorists take over school in Beslan, North Ossetia. Firefight after explosions. Death toll approaching 400 people.

Indonesia

12 October 2002

Australians main victims as nightclub bombings kill 202 people.

5 August 2003

Suicide car bomb kills 12 at hotel in Jakarta.

8 September 2004

Seven die when bomb explodes outside Australian embassy in Jakarta.

Spain

11 March 2004

Back-pack bombs explode on rush-hour trains in Madrid, injuring more than 1,400 and killing 202.

Iraq

19 August 2003

UN envoy and 21 others die when UN headquarters is bombed. Al-Qa'ida involvement in this and other post-war attacks is unclear.

29 August 2003

US blames al-Qa'ida for 80 deaths at mosque in Najaf.

27 October 2003

Car bombs at police stations and Red Cross HQ kill 35 and injure more than 200.

12 November 2003

Italy says al-Qa'ida killed 18 of its officers and nine Iraqis in attack on police station.

Saudi Arabia

12 May 2003

Compound for foreigners in Riyadh attacked by suicide bombers, leaving 34 dead.

8 November 2003

Bomb attack on housing complex in Riyadh kills 17, mostly Arab workers.

29 May 2004

Oil workers taken hostage in Khobar. Three of four captors escape after stand-off with authorities but 22 die.

11 June

Paul Johnson kidnapped in Riyadh. A week later, photos of headless body posted on Islamist website.

Turkey

15 November 2003

Suicide car bombers attack two synagogues in Istanbul killing 25, injuring hundreds.

20 November 2003

Attacks on British Consul and HSBC offices kill 27.

10 August 2004

Bombs explode simultaneously at two hotels in Istanbul. Two die.

Afghanistan

5 September 2002

Car bomb in Kabul kills 25.

7 June 2003

Four German peacekeepers killed in suicide attack on bus.

13 August

Six children and nine adults die in bomb attack on bus.

Morocco

16 May 2003

Four suicide bombs kill 33 people at Jewish, Spanish and Belgian sites in Casablanca.

Pakistan

8 May 2002

Car explodes outside hotel in Karachi leaving 14 dead.

14 June 2002

Bomb at American consulate in Karachi kills 12.

7 August 2004

Two die in bombing outside car rental office. A day later a three-year-old child is one of eight people killed in explosions in Karachi.

Uzbekistan

29 March 2004

Prosecutor General blames al-Qa'ida after series of bombings kill 19.

Tunisia

11 April 2002

Truck explodes at synagogue on the island of Djerba, killing 17.

Kenya

28 November 2002

Three suicide bombers kill 16 at hotel in Mombassa.

Chechnya

9 May 2004

President Kadyrov and 13 others die after explosion at a stadium in Grozny.

Yemen

6 October 2002

Suicide attack on French oil tanker off coast kills one crew member.

30 December 2002

Three Americans die when gunman opens fire in Baptist missionary hospital.

Kuwait

8 October 2002

Two gunmen in truck attack US marines, killing one.

United Kingdom

6 January 2003

Discovery of deadly poison in London flat leads to raid in Manchester in which a policeman is killed.

RELIGION

By Ziauddin Sardar and Paul Handley

It was a wake-up call for Muslims, forcing them to acknowledge that Islam was in total disarray. As a result a new global movement for Islamic reform has been initiated.

Modernists are joining hands with traditionalists, NGOs and governments to rethink what Islam means. In Morocco, Islamic family law has been transformed, restoring gender equality. In Turkey, an Islamic government has introduced reforms to improve human and women's rights, aiming to develop a state that is simultaneously Islamic and democratic and secular.

Christian leaders in the Vatican, in liberal US denominations and in Europe opposed the war in Iraq, and they are critical of the war on terror. Sadly, fanatics fail to notice such distinctions leading to attacks on indigenous Christian communities in Pakistan, north Africa and the Far East.

Meanwhile, the Christian Right in the US doesn't have Bush's advisers to tell them to stop using the word "crusade". The dread is we will wake up one day and realise that Islamic and Christian fanatics were right: there really is a Christian army of occupation in the Middle East. Could there be anything scarier than that?

Ziauddin Sardar's 'Desperately Seeking Paradise: Journeys of a Sceptical Muslim' is published by Granta Books. Paul Handley is editor of the 'Church Times'

TRAVEL

By Simon Calder

American tourists - the highest-spending in the world - have tended to stay closer to home. Airlines have been traumatised - especially the world's two largest carriers, American and United, each of which had two of their aircraft turned into guided missiles on that terrible day.

Both have lost hundreds of millions of dollars in the past three years. But the most extraordinary consequence of 9/11 has been the way that it has encouraged more travel - mainly because the cost of seeing the world has fallen.

After the attacks most airlines wondered by how much they could hike their fares to deal with the downturn in traffic and higher insurance costs.

Michael O'Leary, chief executive of Ryanair, had a better idea: "If you've got 10 quid, I'll fly you anywhere." Within a week, the Irish no-frills airline's flights were full again, and Ryanair enjoyed a market capitalisation greater than that of both American Airlines and British Airways.

Soon, rival airlines found they could cut their fares from the punitive levels they previously charged, and removed restrictions designed to penalise business travellers. Hotels, too, started offering deep discounts to fill beds: with the cost of trips tumbling, people could again remember why they travelled.

All airlines, hotels and newspaper travel sections were reminded of their duty to offer the best possible value to customers. As a result, people are travelling more extensively than ever before.

In a world that needs to be brought closer, that must be a force for good.

Simon Calder is travel editor of 'The Independent'

THE ARTS

By Justin Butcher

The arts are perennially political, just as the targets of satirical and artistic protest - the corruption, brutality and arrogance of wealth and power - are depressingly familiar. Nevertheless, the apocalyptic folly of the Bush administration's response to 9/11 has undoubtedly galvanised artists in different fields to pour out their scorn and outrage in diverse forms.

Michael Moore, winner of best film at Cannes for Fahrenheit 9/11, has led the field to a marching tune played by the Dixie Chicks and Linda Ronstadt, musicians booed on stage and vilified for speaking up. Other artists have also stood up against what Sir Elton John has described as a McCarthyite "atmosphere of fear": Sean Penn leading a peace delegation to Iraq in late 2002; Corin Redgrave championing the legal rights of Guantanamo detainees; Harold Pinter, George Michael, Martin Sheen and Susan Sarandon all vociferously anti-war; the Tricycle Theatre's Justifying War and Guantanamo; Tim Robbins's hit Embedded; and, at the National, David Hare's Stuff Happens.

I received passionate hate mail in more or less equal quantities with fan mail during the run of my show The Madness of George Dubya. It would seem the Cold War weapons of satire and protest are being forged anew.

Justin Butcher's 'Madness of George Dubya' will reopen at the New Players Theatre in London on 18 October