Just in case you wondered what the authorities are doing at this very moment: the police are reviewing 1800 hours of CCTV footage from across London, and the forensic scientists are piecing together the four explosive devices from tons of rubble. Both activities are aimed at finding out who was responsible for the London attacks: the viewing of the CCTV tapes will help to identify the individuals that carried the bombs onto the trains, whereas the reconstruction of the bomb will provide vital clues as to what group was responsible. (Bomb-making is a special skill that terrorist groups entrust to a relatively small number of people. As a result, almost every bomb carries the ‘handwriting' of a particular individual or group.)
At the moment, everything you hear about the identity or the modus operandus of the possible attackers is pure speculation. Generally, though, there are two theories which should be taken seriously. The first is that this was an attack by a completely new group, which has little if any association with the existing networks. This would explain why the police had no indication at all that an attack was on the way. It would also make it plausible why there was no increased chatter or activity among known Islamists, which the intelligence services would have picked up. The second is that this attack is somehow linked to Al Qaeda. This would make sense given the nature of the attacks, which - with multiple, no warning bombings aimed at the transport infrastructure - are almost identical to previous Al Qaeda attacks, most prominently those in Madrid last year. It would also tie in with the two claims of responsibility that have been received thus far.
Considering how sophisticated the attack (some experts estimate that there would have been 30-40 people involved in the planning, the pre-attack surveillance, logistics, etc.), it seems rather unlikely that this was the work of a bunch of deprived Muslim youths, who wanted to take it out on the people of London. At the same time, the Al Qaeda claims are somewhat misleading too. Al Qaeda is not a hierarchical terrorist organisations along the lines of the IRA, with a chief of staff directing and authorising every operational detail. As many authors have pointed out (and Jason Burke is but the most prominent), Al Qaeda is a loose association of networks with a small hardcore. Al Qaeda will support local Islamist groups if it thinks their operations or aims are worthwhile, but has always been reluctant to get involved in the day to day running of Islamist groups. Now that the Al Qaeda leadership is hiding somewhere in the mountains of Baluchistan, it is more than unlikely that Osama bin Laden himself would have directed, or even known of, the next operation to come.
It is instructive to look at the history of the attacks in Madrid as a possible way of reconciling the two theories. Javier Jordan a Spanish professor in intelligence studies - recently published an academic article in which he reconstructed the planning of the attack, as well as the background of the bombers. He concluded that the Madrid train bombings were conceived of by a loose network of Islamists who met through a mosque in Madrid. Crucially, though, they were assisted by at least one so-called Arab-Afghan - an experienced fighter, who had been through one of the training camps in Afghanistan and is likely to have been in touch with Bin Laden or one of his men at some point. This was the link to "Al Qaeda", and while the connection consisted of just one person, it was nevertheless essential. He brought the knowledge and expertise necessary in order to pull off a co-ordinated attack. In other words, he made it the success which, from the terrorist point of view, it undoubtedly was.
If I had to bet my house on one of those scenarios, I would choose the latter. If there was assistance from an Al-Qaeda linked individual, this would explain why the attack was so similar to previous ones, and why it was carried out in such a smooth, professional manner. On the other hand, the total absence of any previous chatter or communication indicates that new people, and perhaps quite a number, were involved, most probably home-grown.
If, indeed, this turns out to be new Al Qaeda model, it may be more dangerous and threatening than the classical terrorism we have seen before. It will become almost impossible for intelligence services to infiltrate these groups, because they are ad hoc and consist of 'new' people with little, if any, previous associations to radical Islamist circles. Unless we want to put the Muslim community as a whole under 24/7 surveillance, it will not be possible to achieve the security that many people rightly expect. It is a tough challenge to answer for everyone who wants civil liberties and multiculturalism in the West to be preserved.
Peter R. Neumann is research fellow in international terrorism at the Department of War Studies, King's College London.