Osama's death: What next for al-Qaeda?
The killing of al-Qaeda leader Osama Bin Laden is a huge blow to the organisation but as guest columnist Ahmed Rashid reports, its decentralised nature means it has the potential to carry out attacks on any number of targets.
There have been cheers and jubilation in the US and elsewhere in the West, but capital cities around the world are already bracing for the repercussions of Bin Laden's killing.
Hundreds of dedicated and would-be jihadis will be mourning and swearing to give their lives in revenge for his death at the hands of US special forces in the city of Abbottabad.
There is little doubt that the death of Bin Laden is a huge blow to al-Qaeda.
But at the same time the network has moved over the years from a highly centralised hierarchy - with recruiting, training and orders all scrutinised by its top leaders - to something much more loose and amorphous.
Today al-Qaeda's philosophy is one man, one bomb. It does not need another 9/11 to make its mark.
One bomb in Times Square in New York placed by a dedicated suicide bomber or a bomb in a New York subway - both attacks were attempted in in recent years - are big enough indicators that al-Qaeda is alive and kicking.
Al-Qaeda has been a franchise for many years.
Anyone can join it by planting a bomb somewhere. Almost anyone can come to Pakistan or Afghanistan and be offered training with key al-Qaeda allies such as the Pakistani Taliban or the Afghan group headed by Jalaluddin Haqqani.
The facilitator in Pakistan's cities has been Lashkar-e-Taiba (LeT) - a banned militant group which previously fought in Kashmir but now attacks many different targets and helps al-Qaeda.
After 9/11 it helped hide many senior al-Qaeda figures and it may well have played a major role in hiding Bin Laden.
Pakistan has refused to go up against al-Qaeda allies like Haqqani because they were operating in Afghanistan not Pakistan.
Likewise, allies like LeT are close to Pakistan's intelligence services because their main target is Kashmir and India.
Thus the threat is there.
Before 9/11 there were no known al-Qaeda cells in Europe except for the one in Hamburg which launched those attacks.
However, today every single European country has an al-Qaeda cell. Hundreds of Muslims with European passports have travelled to Pakistan's tribal areas for training and returned to Europe.
After the arrest of three Moroccans in Germany last week for planning to plant bombs in public places, German authorities admit that over 200 German citizens have had training in the tribal areas and many of them have returned to Germany.
The same is the case in Britain, Scandinavia, France, Spain and Italy.
The fear now of random suicide bombings in subway or train stations in the US or Europe is particularly high.
So is the threat of plane hijackings and bombings of Western military targets and embassies in the Middle East, where they are already a frequent target.
There is also the possibility of the amateur jihadi placing a bomb in a supermarket.
Other kinds of attacks are also likely.
Some may be carried out by dedicated long-term jihadis who have been placed amid Western societies and who now may spring into action with a plot and target that they have been working on for years.
Such lone attackers have been found in the US before, with individuals travelling to the tribal areas for training and then returning to a major US city and trying to carry out an attack.
These have usually been foiled by law enforcement agencies at the last moment.
South Asia risk
Afghanistan, Pakistan and India are also particularly at risk from more organised attacks.
In the former, the al-Qaeda influence among dedicated jihadis like the Haqqani group is still strong.
Pakistan is also extremely vulnerable to attack. Despite a constant spate of denials from the Pakistani authorities - which have now been proven wrong - al-Qaeda recently had its base in Pakistan.
Al-Qaeda and its affiliated Pakistani groups will be determined to launch a bombing campaign in Pakistan in memory of Bin Laden. This will heighten tensions in a country that is already beset with power shortages and an economic crisis.
Finally al-Qaeda and its allies may find this the right moment to create major divisions between India and Pakistan by launching another Mumbai-style attack on Indian territory.
This would aim to take the heat off the hunt for al-Qaeda members in Pakistan.
The Middle East also remains a big vacuum for al-Qaeda because of the ongoing Arab revolt.
It is still a prime target for al-Qaeda as it seeks to gain influence and clout among the new generation of leaders who have emerged in Tunisia, Egypt, Syria and the Gulf states. But this task will be much more difficult after Bin Laden's death.
Clearly Bin Laden's death will give intelligence agencies around the world many clues and leads to catch other leaders, but al-Qaeda will not disappear overnight.
Ahmed Rashid's book, Taliban, was updated and reissued recently on the 10th anniversary of its publication. His latest book is Descent into Chaos - The US and the Disaster in Pakistan, Afghanistan and Central Asia.