Preface: I have zero interests in doing ethical condemnations of the acts of individuals, because on rather fundamental level, individuals act in ways that they see no true alternative to. I am far more interested in understanding the whys of human actions. With that in mind, let’s move forward.
Let me open with an old Finnish joke (I do feel like I am writing a Žižek pastiche, yes). When faced with an issue of any sort, you can always say “They did not have this problem in the Soviet Union.”
The joke, in itself, hides a truth that should be obvious. The Western citizen, or subject, desires in many cases a state that would be capable of action. The cause to take action against differs, it may be political corruption, it may be unemployment or lack of self-determination.
The state exists in many regards in a state of inaction, unless it comes to carrying out the neoliberal (or in recent history, a social democratic) agenda. This creates a fundamental rift between the state and its citizens, who frequently do desire action in ways and for causes that are unpalatable to the state. As an example, there is now a call of action against the racist actions and racist attitudes of the Finnish police, and while the police leadership has been outspoken about condemning racism, action is lacking. When a known racist is put in charge of investigating racism within his own organization, we see this as a false action and fundamentally lacking in meaning.
But what is to be done? Nothing. The individual has no power to influence the machinery and the structures of the state, which water down any calls of action into vague promises of change. This process is so obvious, that anyone who hasn’t accepted the ideology of the state, knows without doubt that any investigation will be pointless and no change will ever happen.
In the neoliberal West, individualism reigns supreme, so there are no serious attempts at organizing against injustice, either perceived injustices (in the case of ISIS-related terrorist actions) or objective injustices. The individual, the subject, realizes that they have become objects for a machinery of state that absolutely has no regard for them. The atomization of society brings along with it not a willingness to resist, but a death drive. When there is nothing that you can do to affect the present conditions, the idea of lashing out, even suicidally, becomes a lot stronger.
Famously, the Rote Armee Fraktion was to a significant degree motivated by the realization that the West German government was absolutely dominated by former Nazis on all levels, and post-denazification, there was no real interest in justice. Baader and Meinhof did, entirely correctly, realize that there was no chance of change within the system in itself, so they rejected peaceful means in favor of violent means.
Note that it does not matter at all that there was no true right-wing conspiracy to make things in West Germany the way there were: the entire situation was happenstance and how a western capitalist state conducts itself. The important thing is how the individual perceives the state to act. And in the case of Baader and Meinhof, they rejected the actions of the state and took to arms, with well-known consequences.
We can also look at the conflict in Northern Ireland, that in the 1960s was characterized by a peaceful civil rights movement by the Catholic population, but quickly became a sectarian conflict, primarily due to Unionist provocations leading to a new rise of the Irish Republican Army.
In both of these cases, we can point towards a process of frustration of the subject. An environment which both empowers the individual, yet completely ignores the individual whenever the individual makes demands that do not interest the state, creates nothing but frustration. If your demands are well represented among the machinery of the state, there are no reasons to feel frustration.
The legitimacy of the desire has little to no effect on the process of frustration. We are still struggling to understand the radicalization among the population in Western countries, that recently have led to actions such as the bombing in Manchester, the attack on London Bridge, the truck attack in Stockholm and so on, yet we can almost certainly say that the individuals who carried out their attacks have had their personal ideology rejected by both the state and the mainstream of popular opinion. Yet, these people are willing to die in actions that only serve as an extended suicide. This is significant in itself.
Terrorism towards a revolutionary goal seems to exist even when the revolutionary goal is impossible, as in the case of the RAF. It is also possible that behind the actions, there is a larger political ideology and a goal that is in it self a rational goal. The Islamic State encourages terrorism, because terrorism drives a wedge between the Muslim population in the West and the general population. This almost nihilistic and distinctly realpolitik goal is however not what results in people being willing to die. Those processes only happen on individual levels and those processes are the process of frustration and de-subjectivization.
Thus, we can rather safely say that the modern state, in its belief in itself and in the impossibility of change, is the incubator of terrorism.