Ayman al-Zawahiri is described as 'more lethal' than Osama bin Laden and has applied his discipline and notable intellect to the cause of jihad since the age of 16 [Reuters]
According to terrorism expert Rohan Gunaratna, Ayman al-Zawahiri is even more lethal than Osama bin Laden. 'Goal-orientated, systematic, secretive and forward thinking', Zawahiri's accession as al-Qaeda's leader marks the return of al-Qaeda with a vengeance.
Certainly, Zawahiri has applied his discipline and notable intellect to the cause of jihad since he was 16 years old. A prolific propagandist, he has penned some of the most influential extremist tracts, including important theological justifications for suicide bombing.
His charisma, however, is more open to doubt - as are his battlefield credentials. The veteran jihadi Abdullah Anas argues that Zawahiri has no credibility. During the jihad against the Soviets in Afghanistan, Zawahiri 'was just sitting in Peshawar, criticising'.
As experts speculate about the future of al-Qaeda under Zawahiri's stewardship, it is worth considering the nature of the beast bin Laden has bequeathed to his deputy. Indeed, Zawahiri takes the reins of al-Qaeda at precisely the juncture during which al-Qaeda may be evolving into a post-leadership phase.
In February 1998, the World Islamic Front against Jews and Crusaders issued al-Qaeda's seminal fatwa. It declared that 'the ruling to kill the Americans and their allies - civilians and military - is an individual duty for every Muslim'. In so doing, the architects of global jihad have re-invented one of the most important Islamic legal ideas regarding authority.
Historically, the idea behind jihad as an individual duty was for Muslim rulers in neighbouring provinces to come to the aid of their co-religionists in other parts of the empire. The assumption was always that all jihads, including defensive ones, would be led by established Muslim leaders within clearly defined communities. In a move that subverted established patterns of authority, the World Islamic Front reached out to Muslims as individuals rather than as members of politically organised communities.
In 1998, what this amounted to was a call by bin Laden for Muslim individuals to come aboard and, quite literally, join them in the caravan of jihad. Going over the heads of the region's rulers and clerics, who had 'sold out the umma for a handful of coins', bin Laden democratised Islamic authority. A layman with no religious training, he formally declared a jihad of self-defence, and called upon his fellow Muslims to individually come forward for training and combat.
More than a decade later - including cycles of counterproductive bloodshed - that call has altered subtly, but significantly. The democratisation of authority has entered a second stage. A new ideological and strategic current is championing lone-wolf attacks by Muslim individuals living in the west, without prior contact with al-Qaeda networks or consultation with any of its radical jurists.
Lately, al-Qaeda's strategists view the Muslim population in the west as their ace in the hole. According to al-Qaeda military strategist Abu Musab al-Suri, the group seeks to increasingly exploit the potential of self-radicalised Muslims who are 'able to be present in the west in a natural way'. These individuals provide al-Qaeda with a broader base from which to project power from. As Adam Gadahn argued in his most recent video appearance, Muslims in the west are perfectly placed to play an important and decisive role, particularly as America is awash with firearms which can be easily obtainable at gun shows without identification.
Furthermore, individual operations are much harder to detect and intercept because, as al-Qaeda's 'Inspire' Magazine points out, nobody else in the world needs to know what these lone operatives are thinking and planning. The global jihad becomes at once universal and highly particularised.
Most importantly, from a strategic perspective, such operations shift al-Qaeda's violence out of the Islamic world and back into the western heartland. In short, their targets are necessarily western. This second wave of democratisation is designed, in many ways, to counter the problems created by the first wave: bin Laden's brand was gravely damaged by the horrific massacres of Muslim civilians perpetrated by loosely affiliated groups. From Afghanistan to Algeria, the bloodbaths which took place under al-Qaeda's banner targeted the very Muslims al-Qaeda was supposed to be protecting.
The aim is to get back to basics and start hitting western targets again. A few successful examples are routinely put forward as models for jihad al-fard (individual jihad): Taimour al-Abdeli, who detonated a car bomb and his own suicide bomb in Stockholm; Major Nidal Hassan, the US military psychiatrist who went on a shooting rampage at the Fort Hood army base in Texas; and Roshonara Choudhry who, seconds after smiling at her local MP, British politician Stephen Timms, plunged a knife into his stomach in May 2010. The latter is most significant because it is believed Choudhry had no contact with any radical recruiters or cells, and plotted her attack entirely alone.
The emergence of the strain of thought privileging terrorism by individuals coincides with the rise of al-Qaeda in the Arabian Peninsula (AQAP), whose ideologists are vigorously re-imagining the landscapes of jihad.
Inspire magazine is AQAP's publication, and its glossy pages increasingly advocate 'individual terrorism'. In the latest edition's letters section, an anonymous Muslim living in the west asks about the best way to reach the jihad frontiers. Stay where you are, he is advised, and focus on planning an operation in the west instead, like attacking an army recruitment centre or a nightclub.
A few pages later, AQAP's military commander, Abu Hureirah, calls for an 'operation in their midst' in response to every drone attack in Waziristan or act of aggression against the Palestinians. It is Abu Hureirah's hope that the magazine will soon offer a military section dedicated to explaining what the Muslim should do on the western front. This would presumably complement the recurring 'Open Source Jihad' section, which advises on how to make a bomb in your mum's kitchen (Issue I) and how to outfit a pickup truck with blades so that it can be used to mow down Allah's enemies (Issue II).
Also associated with AQAP is the charismatic preacher Anwar al-Awlaki,whose fluent English, soft intonation and sharp wit are directed conscientiously at Muslims living in the west [killed recently]. A trained cleric, his religious addresses are suffused cleverly with a very articulate brand of anti-imperial politics. Awlaki was in email contact with Nidal Hassan and his sermons were found on Roshonara Choudhry's computer.
Awlaki's father defends him against terrorism charges by observing that, unlike Osama bin Laden, his son is not a fighter but merely a preacher. However, therein lays Awlaki's potency as al-Qaeda's non-conventional combat doctrine enters a new phase. In the era of individual terrorism, the power to inspire is the most significant force multiplier.
According to a US counterterrorism official quoted by the ProPublica website, Nasser al-Wuhayshi sent a message to Osama bin Laden before his death proposing that Awlaki replace him as leader of AQAP. Volunteering to step aside, Wuhayshi argued that because of Awlaki's popularity in the west, his appointment would be a PR coup and an important spur to recruitment. Bin Laden rejected the proposal, stating that he preferred to leave things the way they were.
It comes as no surprise, then, that Awlaki didn't make the cut as bin Laden's replacement. Still, Awlaki may prove more influential than Zawahiri if the strategy of individual terrorism takes root - perhaps even posing a challenge to al-Qaeda's own established authority structures. With a rise in lone wolf attacks, it will be Awlaki's face which appears in al-Qaeda's new moon.
Dr Alia Brahimi is a Research Fellow at the London School of Economics and Political Science. She is also a Senior Research Associate at the University of Oxford.
Her work examines the moral justifications given for warfare, as well as jihadi ideology and strategy. Her latest book is Jihad and Just War in the War on Terror.
You can follow her on Twitter: @aliabrahimi
The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.