These days there are far more "terrorist experts" earning their living because of their supposed knowledge of al-Qa'ida than there are real members of al-Qa'ida. This is an important reason why the organisation will not fade from the headlines or from the list of threats that governments see as facing their countries despite the death of Osama bin Laden.
None of these "experts", whether they work for governments, intelligence services, the armed forces, the media or in academia, will ever have an interest in declaring al-Qa'ida or groups like it as defunct or irrelevant. Their continued employment, budgets and influence has to be justified by continuous threat inflation.
It is not that Al-Qa'ida poses no threat, but it differs markedly from public perception. The group was never a well-coordinated worldwide network of terrorists answering to a central headquarters in Afghanistan or Pakistan. But after 9/11 it had such a fearsome reputation, and occupied such a pre-eminent place in US demonology, that any hint of its presence was highly publicised and had an immediate international political impact. No government could afford to allow the US to endure another 9/11.
Obsession with al-Qa'ida leads to political tunnel vision. For example Yemen, the mountainous republic tucked away in the south-west corner of the Arabian Peninsula, has a population of 24 million mostly impoverished people, but US policy towards the Yemeni government is largely determined by the activities of an estimated 300 members of Al-Qa'ida in the Arabian Peninsula (AQAP).
This handful of AQAP members do not have to do very much to cause turmoil at airports across the world. Two abortive bomb attempts organised from Yemen last year, both foiled, proved almost as successful in terms of generating disruption and fear as if the bombs had gone off as planned, as AQAP itself boasted.
The way in which the presence of al-Qa'ida has political repercussions out of all proportions to its size is demonstrated above all by Afghanistan. The US military has said that there may be little more than 100 al-Qa'ida members in Afghanistan compared to a Nato estimate of 25,000 Taliban. Yet President Obama's justification for sending 30,000 more troops to Afghanistan to fight in an unpopular conflict was the need to combat al-Qa'ida, which the US public does care about, rather than the Taliban, which it largely does not.
If Afghanistan is not a refuge for al-Qa'ida, how about across the border in north-west Pakistan? The semi-autonomous Federally Administered Tribal Areas (Fata) used to be a place of refuge for al-Qa'ida and was frequently referred to as "the most dangerous place the world", but much of it is now occupied by the Pakistani army and there are continual US drone strikes searching out Taliban and al-Qa'ida leaders seeking sanctuary in its rugged terrain. There was a good reason why bin Laden preferred to live far away from here in his villa in Abbottabad just north of Islamabad.
Many of the remaining al-Qa'ida havens are a series of franchises and several of these are absorbed in local disputes. In Iraq, al-Qa'ida became powerful for several years after 2003 as the Sunni community fought the US occupation and the Shia- and Kurdish-dominated Iraqi government. It drew strength from these struggles, but grossly overplayed its hand by trying to dominate the Sunni and wage war against the majority Shia. These days it seldom attacks US troops, though it continues to wage bloody sectarian warfare against the Shia.
In the Arabian Peninsula, al-Qa'ida retreated from Saudi Arabia to set up AQAP in Yemen in 2009. Its best-known member here is Anwar al-Awlaki, an American citizen speaking fluent English who is one of the few al-Qa'ida leaders who can articulate the group's ideology in convincing terms. He was also linked to the shooting of 13 people by a US army major in Fort Hood in Texas. The street protests in Yemen may make it easy for al-Qa'ida to move around, but also means that opponents of the political status quo now have alternative means of opposing it.
Somalia and the Horn of Africa are probably the best places for al-Qa'ida to gain in strength. Since last year it is allied to al-Shabaab, the Somali group that controls much of the south of the country. It says it was behind suicide attacks in Uganda last year that killed 76 people. From the point of view of a secret movement planning to attack US targets, Somalia – much of which of which has descended into anarchy – has the advantage that militants can cross its land borders without being checked.
Further west, Al-Qa'ida in the Islamic Maghreb – many of its fighters survivors of the Algerian civil war in the 1990s – has a shadowy existence in the Sahara, kidnapping tourists and making occasional forays into the cities. It may have been behind a bomb that killed 16 people in Marrakech last week, but as a movement it does not seem to be going anywhere.