Recent developments in the degradation of Islamic State (ISIS), from the loss of the territory it controlled to the death of its leader Abu Bakr al-Baghdadi, has substantially impacted  the capabilities of the group to carry out terrorist attacks globally. However, it remains clear that ISIS continues to exert significant influence through its ideology that is influencing a variety of individuals to sustain the extremist ideology and to consider terrorist attacks.

Two recent reports from international organizations, one from the European Union Agency for Law Enforcement Cooperation (Europol) and the other from the United Nations Security Council, provide assessments that while terrorist attacks are diminishing, the ideas and ideology that ISIS inspires continue to pose a threat globally, and in particular, to the security of the EU.

The 2019 EU Terrorism and Situation Trend Report published by Europol provides evidence that the total number of terrorist attacks taking place in the EU have reached a four-year low. The report does indicate an increase in attacks and arrests in relation to terrorism motivated by ethno-nationalist/separatism or right- and left-wing ideologies, and makes clear the threat from jihadist violence continues to be a strong concern.

The Security Council report, part of the ongoing monitoring of ISIS and al-Qaeda, says that while the geographical caliphate is gone, Islamic State is consolidating and seeking to reinvent external capabilities for carrying out attacks around the world.

Both reports indicate a number of areas where the threat from ISIS-inspired ideology remains potent – violence by lone actors, the situation of returning terrorist fighters, and individuals in prisons.

That final point, of individuals in prisons being susceptible to ISIS ideology, will pose a significant issue for the EU to address. There are a number of elements to this, such as the increase in arrests and convictions for terrorism offenses, and the issue of returning fighters from Syria who may be facing jail sentences for their time fighting for ISIS. The Europol report indicates there are growing trends in prisons where ISIS-inspired inmates are maintaining the ideology and influencing others.

This will be an important point of attention going forward. The end of the physical existence of the ISIS caliphate has had a substantial impact on reducing the group’s ability to be an active threat. The group no longer has the capability to organize directly or carry out attacks in Europe effectively. Its ability to influence through online propaganda is also diminished, but not completely, as both reports make clear.

The defeat of the caliphate also works to minimize the lure of ISIS, as there is no opportunity for individuals to join something tangible. There remain a number of ISIS-affiliated groups, al-Qaeda-linked groups, and other jihadist terrorist groups around the world, but none have the appeal that the ISIS caliphate in Iraq and Syria held. For Europe, however, there is an increased threat of individuals carrying out attacks on European territory.

None of this can lead to a belief that the overall security threat posed by ISIS and other jihadi-affiliated groups is going away. The ideology and worldview of ISIS continues to attract. This ideology is grounded in the belief that society needs to be organized around a particular interpretation of Islam that glorifies the past, emphasizes the most austere interpretations, and offers no space for discussion or debate.

The ideology is not exclusive to ISIS, as variations have been embraced by a wide range of terrorist groups and their supporters. Equally the core ideas of the ideology – the embrace of a particular interpretation of Islam – are also held by non-violent extremist groups who seek to achieve the objective of a caliphate-like system but through means other than violence. It is important for the EU to maintain cognizance of the core ideas in the ISIS ideology, which have significant influence across a spectrum of supporters.

The influence or embrace of the ideology does not lead to violence in all cases but it does feed into ideas, attitudes and practices that challenge understandings of security in the EU. It has been shown how the embrace of certain Islamist ideologies has divided communities in the EU and have contributed to violent attacks. The Europol and UN reports emphasize that ISIS ideology continues to have resonance across Europe in relation to vulnerable individuals, returnees, and those in prison. The EU report also speaks of the challenges posed by overseas groups that embrace the ISIS ideology and make use of it to sow discord globally and that also influences jihadi affiliates in Europe.

The Europol report shows that the majority of EU states did not report jihadist terrorist attacks in 2018. At the same time, across the member states reporting terrorist crimes, jihadist-inspired terrorism is the most prevalent. In looking at the foiled, failed ad completed attacks in 2018, jihadist terrorism accounted for 24 instances, while ethno-nationalist/separatist constituted 83 of the instances. However, nine member states experienced jihadist terrorism, whereas only three experienced ethno-nationalist/separatists attacks.

The same holds for the number of reported court cases dealing with jihadist terrorism, where 15 member states had such trials, while ethno-nationalist/separatists trials took place in only five member states. The report holds that the “vast majority” of verdicts across the EU concerned jihadist terrorism, confirming a trend starting in 2015 where the bulk of security operations and subsequent court cases deal with jihadi-affiliated terrorism.

These are important figures to keep an eye on, as they mean that more member states have ISIS-inspired jihadis in the prison system. Both reports explain how individuals are motivated to act, and the arrest figures and court verdicts provided in the Europol report demonstrate extensive planning being undertaken across the EU. This has strong implications for security in the EU, as individuals supportive of ISIS ideology no longer have the physical manifestation of the caliphate to travel to, resulting in their actions being applied locally. The decline in jihadi-inspired attacks is due more to the lack of competence and capabilities of the perpetrators and not a diminution of the ideological influence of ISIS.

Both reports speak of the influence of ISIS ideology on vulnerable individuals who are indoctrinated easily and then motivated to pursue terrorist acts. Even the returnees from the physical caliphate who realized the project had failings remain tied to the extremist ideas ISIS epitomized. The Europol report speaks of an increasing number of adherents to ISIS ideology across the EU, in particular in relation to prisons and returnees.

The influence of ISIS ideology in prisons is going to be prove difficult to address. The reports speak of more individuals being arrested and convicted in the past years, putting them in contact with experienced jihadis already in prison. Returnees who have been arrested and sentenced are adding to the prison population holding on to ISIS ideology, and this number is likely to increase with the destruction of the caliphate and more individuals returning to Europe.

The UN report suggests states are concerned about the current situation being only a lull in activity, not a proper reduction in the threat posed by ISIS-inspired violence. The executive director of Europol says that overall the level of terrorist threat across the EU is not diminished, rather “the situation has become more complex.” The complexity is heightened further by the situation where reciprocal extremism is becoming more prevalent in the EU.

Europol explains: “Within the jihadist milieu, multiple actors of diverging motivation and allegiance are plotting alone or conspiring with others; and right-wing extremists, in a bid to justify violence, prey on the perception of a threat from Islam.…” This circle of reinforcing extremist narratives is prominent in prisons and regularly used by jihadis, as they can claim the entire criminal justice system shows how their beliefs are hardened. The ideology of ISIS will continue to fuel extremist views in complex ways.

With the degradation of ISIS we cannot be complacent that the threat of jihadi terrorism is subsiding. In many ways the reports for Europol and the UN show a more complex threat is now present. Both reports make clear that even though ISIS is clearly no longer the organized entity it once was, its beliefs, its worldview and the project it was pursuing continue to have influence. This influence is particularly pronounced in European prison systems, as we have already experienced attacks in France and Belgium led by individuals with a record of being influenced in prisons.

The situation in Europe is proving that terrorist attacks are motivated by a range of factors and simplistic explanations claiming that crime or other factors alone explain actions are not holding up. The strength of ISIS ideology is being held up by those already in prison and is being used to influence a wide range of vulnerable individuals.

It is unfortunate that greater effectiveness by the European police and security services in preventing terrorist attacks is going to result in a larger pool of individuals potentially influenced by ISIS ideology and susceptible to carrying out or influencing attacks in the future. The security situation in the post-ISIS landscape is undoubtedly becoming more complex.