If you survey the individuals that have undertaken these attacks then some common trends emerge which refute the two dominate arguments.
One, they are usually not recent immigrants. Two, they tend to not lead strict Islamic lives and engage in "decadent" Western behaviours. Three, they are often dysfunctional, social outcasts with no clear or comprehensible underpinning ideology.
However, beyond the surface traits of these individuals, something of a psychological commonality exists, which is that these perpetrators are predominately nihilistic.
According to the Internet Encyclopaedia of Psychology, nihilists are people that "believe in nothing, have no loyalties, and no purpose other than, perhaps, an impulse to destroy". Therefore, for these perpetrators, it is likely that adherence to radical Islam or anger about Western intervention abroad are merely frameworks for their action, not the underlying drivers.
Nihilism as a force of terrorism is not a new thing.
Indeed, many paint this recent form of terrorism that targets civilians indiscriminately as being unprecedented and completely divorced from the political form of terrorism that dominated Europe in the 1970s and 1980s (the type practised by the IRA or ETA).
However, the anarchist terrorists of the 19th century were eerily similar to today's terrorists.
Take, for example, the Liceu Opera bombings in Barcelona that occurred in 1893. An anarchist by the name of Santiago Salvador threw two bombs into the crowded theatre during a performance of William Tell killing 20 and seriously injuring at least 50 others.
Such a gruesome event is reminiscent of what happened at Manchester Arena a few days ago or at the Bataclan in Paris in 2015. Just like Santiago Salvador, the Manchester attack suspect, Salman Abedi, appears to be a man full of hate and without a coherent moral compass (a bona fide nihilist).
The problem that arises if you are persuaded by the nihilistic argument is that there are no easy or obvious solutions to combating nihilism. Sadly, Europe's experience of nihilistic terrorists in the 19th century does not really offer any possible policy prescriptions because it is probable that the problem of anarchist terrorism died out because of the world wars that emerged in the 20th century.
The policy options currently touted seem to range from deeper security measures and better intelligence to more (or less) intervention in the Middle East and North Africa.
However, these policy prescriptions are superficial and do nothing to address the nihilistic element of this terrorism. In fact, these policies could create more nihilism - especially if they limit freedoms - and, in turn, possibly more terrorism.
The question which needs addressing the most is not 'how can we stop these individuals from acting on their nihilism' but rather 'how can we stop these individuals from becoming nihilistic in the first place'?
Part of the problem is surely the decay of Western societies. Our societies have become less democratic, more unequal and more corrupt and there is a real sense of disenfranchisement. Additionally, our societies have lost confidence in their ideological heritage. The core enlightenment values - rationality and liberty - are no longer cherished or held up as aspirational standards, but are rather shunned causing an ideological void.
Closing this ideological void - perhaps by re-embracing enlightenment values or finding something new - and taking steps to improve our decaying societies - maybe through democratic reform and fairer social policies - are the two remedies that come to mind.
The problem is that these are not things that can be easily achieved through implementing specific policies. Rather, they require solutions which are much wider and deeper in scope and focus on not only the short-term but the long-term as well.
Moving beyond the competing monocausal explanations for the current spate of terrorist attacks and accepting that there are deeper drivers of these attacks is a necessary step to finding solutions which can make a difference.
- Dr Nicholas Ross Smith is a postdoctoral fellow at the University of Canterbury's National Centre for Research on Europe.