US President George W. Bush forewarned in declaring his war on terrorism that the fight would not be easy. 'A lengthy campaign, unlike any other we have ever seen' was how he portrayed the coming battle in an address to a joint session of the US Congress on September 20, 2001.
Mr Bush may not have known exactly what he was getting his country and its allies into, but five years on, his words ring true. Insurgencies rage in Afghanistan and Iraq, hundreds of civilians die in continuing bombings, new terrorist plots are revealed with frightening regularity, and western governments grapple with the growing phenomenon of homegrown terrorism.
In his speech, the United States leader outlined a strategy that he hoped would lead, 'in the months and years ahead', to life returning 'almost to normal'.
Security and terrorism experts contend that despite the invasions of Iraq and Afghanistan, and despite unprecedented inter-governmental co-operation, life is far from normal. In fact, many believe that making the world a safer place needs a far different approach.
That view is now even shared by Mr Bush's closest ally, British Prime Minister Tony Blair. During a visit to Los Angeles last month, he called for a change of strategy, involving an 'alliance of moderation' that would fight terrorism using values as much as military force.
There is good reason for a rethink. The London bombings on July 7 last year - as well as subsequent alleged plots in Britain, Australia, Canada and the US - involved Muslims born or raised in those countries.
David Wright-Neville, a senior lecturer at Australia's Monash University, said terrorists in non-western nations had often been 'homegrown', but the problem caught authorities off guard.
'Terrorism is a form of learned behaviour and there is something about the way of the world and how we have responded to the events of September 11 that is intensifying the social and political dynamics creating this mindset,' Dr Wright-Neville said from Melbourne.
'This speaks to feelings in the west of alienation, cultural affinity, isolation and marginalisation; it has developed to the point that conventional nation states don't know how to deal with it.'
He said efforts by western leaders to reassure Muslim communities at home were counteracted by the military actions in Iraq and elsewhere in the Middle East. Dissatisfaction had turned to anger, producing new potential terrorist recruits.
Anti-western feelings among Muslims are being strengthened by the rising death toll of Iraqi civilians, estimated by some observers at more than 45,000, as well as the widespread belief that the war there was not about terrorism, but oil.
Professor of peace studies at Bradford University in England, Paul Rogers, said international opinion was now more anti-American than on September 11. During the 1990s, extremist Muslims would go to Afghanistan to train for a jihad, now they were going to Iraq.
'There is a regular pathway of young men who go from Algeria, Saudi Arabia and elsewhere to Iraq to help the insurgency for a few months and use the knowledge gained for possible fomenting of disorder in their own countries,' Professor Rogers said. 'Jihadists from Afghanistan now go to Iraq for combat training and take their methods and techniques home for use against coalition troops. It is all too easy for al-Qaeda propagandists to represent Iraq as a neo-Christian, Zionist occupation of the heartlands of the Islamic world.'
Al-Qaeda forces were decimated and scattered after the Afghanistan invasion, even though Osama bin Laden escaped.
Terrorism researcher and journalist Peter Taylor, whose three-part television series, The New al-Qaeda, debuts on the Discovery Channel on Monday, said that as a result, the group had been forced to change radically and had become more an idea and a movement. He said like-minded groups around the world did not necessarily have direct contact with al-Qaeda, but they shared bin Laden's philosophy of fighting a global holy war against Jews, Christians and the US.
Taylor does not believe that al-Qaeda is fully spent. The Bali bombings in October 2002 had direct links to the group, and the alleged plane bombing plot uncovered in London on August 10 also bore the hallmarks of its direction.
'This doesn't necessarily mean that Osama bin Laden and [his lieutenant] Ayman al-Zawahiri and their people sitting in caves in Afghanistan are plotting and planning it,' Taylor said. 'What it does mean is that people who are members of al-Qaeda or directly connected may have been the intermediaries that organised the training, the logistics and the finance for the alleged plot .
'Yes, al-Qaeda has changed, but it would be wrong to believe that the central organisation no longer exists.'
Experts agree the group and its followers still pose a dangerous threat. In addition, terrorism expert with the Institute of Strategic and Defence Studies in Singapore Rohan Gunaratna said Iraq-based groups were now a threat to Asian countries. The possibility of more attacks in Indonesia, the Philippines and southern Thailand had escalated, he contended, because their governments were not able to adequately deal with the problem.
Potential attackers were now so many that identifying them was 'like looking for the proverbial needle in a haystack', said Paul Wilkinson, the chairman of the Centre for the Study of Terrorism and Political Violence at the University of St Andrews in Scotland. The threat was specifically directed at the US, Britain and Australia for their military involvement in Afghanistan and Iraq, but terrorism was definitely a global worry.
'We shouldn't consider any country as being immune from their activity because they see themselves as waging a global jihad,' Professor Wilkinson said. 'They're taking advantage of fault-lines between the Muslim and non-Muslim worlds everywhere where they hope to exploit the disillusionment and alienation of small groups of young Muslims.'
Oct 12 2002
202 people, including 11 Hongkongers, die in Bali nightclub bombings
May 12 2003
26 die, 160 injured in US expat compound bombings in Riyadh, Saudi Arabia
May 16 2003
41 dead, 100-plus injured in Casablanca blasts
Nov 15 and 20, 2003
57 dead, 700 injured in four blasts across Istanbul
Feb 27 2004
Abu Sayyaf claim 116 lives in Philippines ferry bomb
Mar 11 2004
191 dead, more than 1,500 injured in Madrid train bombings
Sep 9 2004
Australian embassy in Jakarta bombed, killing eight Indonesians
Oct 7 2004
Three car bombs kill 34 and injure 171 Israelis and tourists in Sinai Peninsula
Jul 7 2005
56 dead, 700-plus injured in four bombs on London trains and a bus
Jul 23 2005
Car bombs kill 88, injure 100-plus at tourist resort of Sharm el-Sheikh, Egypt
26 dead in a series of blasts in Bali resorts
Nov 9 2005
60 dead, 120 injured in hotel bombings in Amman, Jordan
Jul 11 2006
Series of blasts on Mumbai communter trains kill at least 200 and injure 700