One of the stranger consequences of early 21st-century terrorism and the rise of militant Islam is that it has induced a nostalgia for an earlier kind of terrorist. The replacement of political ideology with religious fanaticism has eroded the self-imposed constraints that limited terrorist violence in the past. In the 1970s and 1980s, terrorist factions issued communiqués explaining their political agendas, their demands were clear and their targets were specific and comprehensible. In those days groups, such as the German Red Army Faction and the Italian Red Brigades, engaged in highly selective acts of violence. However radical or revolutionary these groups were, the majority were conservative in their operations, using a very limited tactical repertoire directed against a narrow set of targets.
In that period terrorists wanted - to use the often-cited observation by Brian Jenkins, director of the security and subnational conflict programme of the RAND Corporation - "a lot of people watching and a lot of people listening and not a lot of people dead". Now things are different. What we have now is fanatical individuals (the so-called lone-wolfs) and a series of loose, mutually reinforcing and quite separate international networks whose followers combine medieval religious beliefs with modern weaponry and a level of fanaticism that expresses itself primarily in suicide bombings and a willingness to use indiscriminate violence on large scale.
It is not flippant to suggest that Islamist terrorists would inspire less public apprehension if they confined their murderous designs to politicians, diplomats, policemen, judges and soldiers, as did the more "traditional" ideological and ethno-nationalist organisations that dominated the terrorist scene from the 1960s to the 1990s. The threat of indiscriminate terror, even if our intelligence and police work improves a great deal, will be with us for some time and this makes it all the more important to deal with the root causes of this type of terrorism rather than simply to try to defend against it, as we have been doing for quite some time. Western policies since 9/11 have been primarily focused on capturing or killing the jihadis rather than trying to work out what motivates them and why some communities support them.
Political extremists tend to imitate each other and after the Nice and Berlin attacks just before Christmas it was for London more a question of when rather than if. Stopping an individual terrorist attack of this type is the hardest attack to stop, let alone prevent. But it is important to remember all those many attacks that never materialised because of the vigilance and prevention strategies of UK's counter-terrorism forces. Yesterday's terrorist attack traumatised all of us living in the UK but we should not allow it to poison and divide us.