THE United States needed to eliminate Osama bin Laden to fulfill our sense of justice and, to a lesser extent, to end the myth of his invincibility. But dropping Bin Ladens corpse in the sea does not end the terrorist threat, nor does it remove the ideological motivation of Al-Qaedas supporters. Often forgotten amid the ugly violence of Al-Qaedas attacks was that the terrorists declared goal was to replace existing governments in the Muslim world with religiously pure Islamist states and eventually restore an Islamic caliphate. High on Al-Qaedas list of targets was Egypts president, Hosni Mubarak. The protesters of Tahrir Square succeeded in removing him without terrorism and without Al-Qaeda. Thus, even before Bin Ladens death, analysts had begun to argue that Al-Qaeda was rapidly becoming irrelevant. With Bin Ladens death, it is even more tempting to think that the era of Al-Qaeda is over. But such rejoicing would be premature. To many Islamist ideologues, the Arab Spring simply represents the removal of obstacles that stood in the way of establishing the caliphate. Their goal has not changed, nor has their willingness to use terrorism. In the months ahead, Bin Ladens death may encourage Al-Qaeda to stage an attack to counter the impression that it is out of business. The more significant threat, however, will come from Al-Qaedas local affiliates. Bin Laden and his deputies designed Al-Qaeda as a network of affiliated groups that could operate largely independently to attack America, Europe and secular governments in the Middle East in order to establish fundamentalist regimes. Once in place, the network no longer needed Bin Laden and, in fact, has been proceeding with minimal direction from him for several years. The affiliates that Bin Laden helped to create, including Al-Qaeda in the Arabian Peninsula and Al Shabab in Somalia, are still recruiting and financing terrorists and training them for attacks. Neither the events of Tahrir Square nor the raid on Bin Ladens hideout is likely to significantly diminish the appeal of Islamist extremism to those who have been receptive to it. In many Muslim societies, there remains a radical stratum born of a sense of victimization by the West, fueled by inefficient and corrupt governments, and carried forward by an enormous youth population. Al-Qaeda was and is simply a pressure valve, an early form of connective social media that allowed youths fed up with the West and their own governments to organise and vent their anger. Believing that their religion requires them to act violently against nonbelievers in the West and impure, apostate Muslim elites, the extremists will not be stopped by the elimination of Al-Qaedas leader or even by the eradication of Al-Qaeda itself. They will continue their struggle, refusing to renounce violence or accept more democratic, less corrupt regimes as a substitute for the caliphate. Just because we do not always know the identities of their leaders or see a named and hierarchical organisation does not mean that extremists are not working hard to seize the fruits of the Arab Spring. The challenge for the United States is not merely to take advantage of the intelligence gained in the Pakistan raid to further erode Al-Qaeda, but to assist moderate Muslims in creating a counterweight to violent extremism, with both an appealingly articulated ideology and an effective organisational structure. The government that was overthrown in Egypt was corrupt and feckless, as are the regimes now under siege in Libya, Syria and Yemen, but the groups poised to take advantage of the upheaval in those countries include many who share Bin Ladens vision. Similar situations exist in Afghanistan and Pakistan. Moderate, tolerant and even some secular groups exist, but they often do not have a comprehensive alternative vision, know how to communicate it or have the organisational skills to promote it. American and European experts can assist them in building politically viable organisations, but to succeed these new groups must be homegrown and tap into the Arab and Islamic traditions that speak to many Muslim youth. Moreover, without investment to create jobs, new governments in these countries will fail under the weight of youth unemployment. Unless corruption is replaced with efficiency, investment will either not materialise or be wasted. Without alternative movements with vision, appeal, and the ability to deliver change, existing organised extremist groups will fill the void. And despite his death, Bin Ladens goal may yet be achieved. Richard A Clarke, the counterterrorism coordinator at the National Security Council from 1993 to 2001, is the author of Against All Enemies: Inside Americas War on Terror. NYT