In recent months, four separate terrorist attacks, two of which succeeded and two of which did not, have provided us with fascinating, although incomplete, insights into the dynamics of terror, recruitment and radicalisation. In November, Major Nidal Hassan, a psychiatrist of Palestinian descent who was working for the US military, opened fire at the Fort Hood army base in Texas, killing 13 people. Hassan, who was slated to be deployed to Iraq, seems to have had only tenuous connections to either al Qa'eda central or a franchise. He was in touch with a fundamentalist Yemeni imam, Anwar al Awlaki, and had espoused radical views, but he had not received indoctrination or training abroad. Importantly, Hassan struggled with how to reconcile his views as a Muslim and his revulsion for the Iraq war with his duties as an American serviceman.
The question is whether he acted alone out of anger, perhaps after his imam or someone else planted the seeds, or whether he received prompting or even orders from an as-yet unknown party. His choice of targets is telling: the soldiers he attacked were also due to be deployed to Iraq and, in his mind, perpetuate the occupation there. In any case, Hassan is the best example of a terrorist "lone wolf" to date.
Then on Christmas Day, Umar Abdulmutallab, a young Nigerian man from an affluent family who had studied engineering in London, attempted to blow up an airplane carrying 290 people over Detroit. Fortunately, he proved incompetent. According to people who know him, he is religiously conservative and socially introverted but showed no sign of radicalisation until recently. Investigators and journalists are busy retracing his path and determining when, why and how he espoused radical views and who incited him to act. In fact, he had travelled to Yemen where he may also have contacted al Awlaki.
A week later, a Somali man who had gained asylum in Denmark broke into the apartment of Kurt Westergaard, a Danish cartoonist who drew one of the controversial depictions of the Prophet Mohammed three years ago. The would-be assassin, who was not named by Danish authorities, may claim he was fulfilling his religious duty, but he was not a freelancer. He has deep connections to the Al Shabaab movement, an al Qa'eda-linked Islamist group fighting the Somali government.
Then there is the case of Humam Abu Mulal al Balawi, the Jordanian doctor-cum-jihadi who blew himself up at a CIA station in Afghanistan in late December, killing seven US agents and his Jordanian handler. The man had served as a physician in Palestinian refugee camps, was outraged by the Israeli war on Gaza and had links to Arab militants who had fought the US military in Iraq. In a video broadcast after the attack, he claimed that he was conducting the operation to avenge the August 2009 killing of Baitullah Mehsud, a leader of the Pakistani Taliban, by a US air strike. Clearly, in al Balawi's mind, there was continuity between these theatres in the form of US aggression.
In fact, an unpleasant truth is that terrorism is often a reaction. A few years ago, the US political scientist Robert Pape published a study of hundreds of suicide attacks and concluded that most were conducted with the strategic intent of forcing the target - in this case combat forces operating in foreign countries - to withdraw. Pape made a direct link between occupation and martyrdom operations. In a way, Hassan and al Balawi fit that model, identifying with Muslim nations they perceived to be under occupation even if they were not citizens of those countries.
But Pape's framework leaves a lot unanswered about modern terror. In Abdulmutallab's case, did occupation really led to radicalisation? Hassan had few links to Palestine and none to Iraq, so does a sense of alienation not also explain his killing spree? Is al Qa'eda's agenda by nature defensive, or is it not also ambitious and expansive, as argues the French scholar Olivier Roy? And to what extent do religious justifications of terrorism, however outside the mainstream, facilitate the jump from anger to action?
The scholarly work on radicalisation and recruitment since the attacks of September 11, 2001 has produced fascinating findings, including exposing the flimsy correlation between poverty and terrorism. Terrorists often come from middle class backgrounds, and are often idealists who see themselves as acting for the greater good of the community or losers seeking a sense of purpose and belonging in radical groups or on the internet.
To be sure, these four men represent only a fraction of the terrorist spectrum as it stands today. Attacks happening daily in Afghanistan, Pakistan, Iraq, Yemen and elsewhere have perpetrators who won't achieve the same fame, and thus won't invite the same scrutiny. But for policymakers and security professionals, it is deeply troubling that, taken together, these men represent the new, globalised face of al Qa'eda.
Once believed to be decisively weakened, al Qa'eda has reinvented itself as a franchise that is diversifying its threats, establishing new bases in failing states and recruiting operatives who undergo radicalisation in Europe or the US, travel to these states for training and go back to create mayhem. Unsurprisingly, the international response will range from stricter airport security to more drone attacks. But the past eight years have taught us that the most effective way to weaken al Qa'eda's appeal is a sustained counter-radicalisation strategy that undermines its storyline. Community outreach and co-operation with religious authorities to empower moderate Islam and emphasising extremists' crimes against civilians, mostly innocent Muslims, can discredit the romantic narrative of resistance and martyrdom.