Even as Westerners celebrate the death of Osama bin Laden, cities around the world are bracing for repercussions. Hundreds of dedicated jihadi wannabes will be in mourning today and swearing to give their lives in revenge for the killing of Bin Laden by U.S. forces in the Pakistani city of Abbottabad.
Bin Laden's death is a huge blow to the terrorist network, but at the same time, Al Qaeda has moved over the years from a highly centralized hierarchy with recruiting, training and orders all filtering down from top leaders to a much more loose and amorphous organization.
Today the group's philosophy is one man, one bomb. In other words, it does not need another 9/11 to make its mark. One bomb in Times Square in New York placed by one dedicated suicide bomber, or one bomb on a New York subway — both things that were attempted last year — are now considered big enough statements.
Al Qaeda's decentralization has ensured it will remain a viable franchise for some time. Anyone can join by planting a bomb somewhere. And almost anyone who travels to Pakistan or Afghanistan can receive training from Al Qaeda allies, such as Lashkar-e-Taiba, the Pakistani Taliban or the Afghan group headed by Jalaluddin Haqqani.
Pakistan has refused to go up against Al Qaeda allies like Haqqani because they have up to now waged their attacks in Afghanistan, not Pakistan. Allies like Lashkar-e-Taiba are tacitly tolerated because their main targets are Kashmir and India.
Before 9/11 there were no known Al Qaeda cells in Europe except for the Hamburg cell that launched the 2001 attacks. Today every European country has an Al Qaeda cell, and hundreds of Muslims with European passports have traveled to Pakistan's tribal areas for training and then returned to Europe.
After the arrest of three Moroccans in Germany recently for planning to plant bombs in train stations, German authorities acknowledged that more than 200 German citizens have received 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 threat of random suicide bombings in the U.S. and Europe is particularly high. So is the threat of plane hijackings and bombings of Western military targets and U.S. embassies in the Middle East.
Attacks are likely. One type will be that carried out by dedicated long-term jihadists already living in Western societies as "sleepers." They may now be expected to spring into action with carefully honed plots they have been working on for years. The U.S. has previously derailed such attacks at the last moment.
There is also likely to be an uptick in terrorism in Afghanistan, where Al Qaeda's influence among dedicated jihadists like those in the Haqqani group is still strong. Al Qaeda and its affiliated Pakistani groups will also be determined to launch a bombing campaign in Pakistan in memory of Bin Laden, which will heighten tensions in a country 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, which would aim to take the heat off of Al Qaeda members in Pakistan.
The Middle East, with the ongoing Arab revolts, remains a vacuum that Al Qaeda will try to fill despite the setback of Bin Laden's death. The group will undoubtedly try to gain influence and clout among the new generation of leaders who have emerged in Tunisia, Egypt, Syria and the Persian Gulf states — except that task will be much more difficult.
Al Qaeda faces difficult days ahead, and 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, a Pakistani journalist and the author, most recently, of Descent Into Chaos: The United States and the Failure of Nation Building in Pakistan, Afghanistan, and Central Asia. His book Taliban has recently been updated and reissued on the 10th anniversary of its publication. A version of this piece appears on the BBC's website.