Returning Forgein Fighters 

Daesh’s leader was killed in a US-led operation in October 2019...
Most Western Daesh fighters who have returned to their home countries will probably not engage in terrorist activity. However, those who stayed loyal to the terror group as its so-called ‘Caliphate’ collapsed likely remain committed to Daesh’s ideology and hostile to the United Kingdom. While abroad, the threat these individuals pose to Britain is marginal. Those who succeed in returning to Britain will face sanctions, including criminal prosecutions. However, the difficulty of securing convictions, and the limitations of monitoring and deradicalization programmes mean that these individuals will continue to represent a potential threat for the foreseeable future.

By Eden Stewart, Senior Analyst and Callum Yourston, Analyst: Risk Awareness Team

How much of a threat are returning Daesh fighters to Great Britain?

“While the vast majority of returnees are unlikely to engage in terrorist activities, a minority will almost certainly retain the intent to conduct or facilitate atrocities.”

The Turkish offensive into northern Syria last October saw Syrian Democratic Forces (SDF) abandon its positions along the country’s border, including at several detention facilities which held captured Daesh fighters and their dependents. This raised the spectre of mass escapes by detained fighters, amongst whom are roughly 2,000 foreign (i.e. non-Iraqi or Syrian) terrorist fighters (FTFs). Shortly after beginning its Syrian incursion, Turkey announced that it was to deport the over 2,200 foreign Daesh members which it held. These developments underscored the long-running concerns over the threat FTFs pose to their home countries.

The precise number of Britons held either by Turkey or the SDF is currently unclear. Roughly half of the 900 individuals who travelled from the UK to join Daesh had returned by the end of 2017, with a further 200 estimated to have died in the region. Only a handful are believed to be in Turkish custody, and fewer than 100 are estimated to be in SDF-run camps, with women and children ac-counting for many of these. This suggests that around 200 British Daesh members remain at large, either in the Middle East, in other Daesh ‘provinces’ in North Africa and South Asia.

Despite the large number of British FTFs who have al-ready returned to the UK, the focus on those still ‘in theatre’ is understandable. Many of those who returned prior to 2018 will have become disillusioned with Daesh or the reality of life in a warzone. Furthermore, most will have returned knowing that they would be subject to police investigations and potentially criminal prosecutions. These individuals will probably have disengaged from violent extremism, even if they have not entirely disavowed radical beliefs.

Those still in the Middle East will be, for the most part, the most committed of FTFs and are less likely to have rejected Daesh’s authority or ideology, and as such, they represent potentially the greatest threat to the UK. Those in a position to do so are likely to go into hiding in Iraq and Syria, or to travel to other areas of the world where Daesh has a presence. From here, many will seek active combat roles and therefore represent a negligible threat to Great Britain. However, some will likely attempt to direct or instigate attacks from abroad.

Are British fighters a threat to the UK while overseas?

While terrorist ‘instigators’ enjoyed considerable success from 2014, the attrition of Daesh’s communication capabilities, improved intelligence, and the damage done to the group’s brand have reduced its ability to incite or direct attacks remotely. The involvement of a small number of fugitive British FTFs in propaganda and incitement efforts is unlikely to materially increase the frequency of attack planning in the UK, unless accompanied by a wider revitalisation of Daesh’s information operations.

Those FTFs who do return to the UK are a more pressing concern. It is unlikely that fugitive FTFs will be able to return to Britain undetected, given the UK’s strong border security and the resources devoted to tracking and identifying FTFs. However, returning FTFs, even when deported by regional authorities, may prove difficult to prosecute. Only one in ten of those who had returned to the UK by the beginning of 2019 had been successfully prosecuted, largely due to the difficulty of gathering sufficient evidence from conflict zones. The recently passed Counter-terrorism and Border Security Act, which makes it a criminal offence to enter or remain in designated areas, may improve conviction rates, but some returnees will probably to avoid jailtime nonetheless.

Returnees who cannot be prosecuted can be subjected to Terrorism Prevention and Investigation Measures (TPIMs) and Temporary Exclusion Orders which require suspects to periodically report to police, and restrict their movements. These measures may go some way in deterring suspects from engaging in extremist activities, and those considered the greatest risk will be subject to more intensive monitoring by police and MI5. However, as demonstrated by recent events, aspiring terrorists can plan, resource and execute low-complexity attacks in very short timeframes, without their intentions becoming known to authorities. Therefore, while risk management measures will probably be effective in stopping more sophisticated multi-person plots, they are unlikely to succeed in preventing attacks which employ more rudimentary methodologies.

Will they impact the future frequency and severity of attacks in the United Kingdom?

Given this, the Government’s reluctance to repatriate FTFs detained abroad is understandable. However, it may be obliged to accept the return of at least some of the Britons currently held in the Middle East. While the vast majority of returnees are unlikely to engage in terrorist activities, a minority will almost certainly retain the intent to conduct or facilitate atrocities. Although their capabilities will be limited by the suppressive effects of counter-terrorism efforts, unsophisticated attacks will prove hard to prevent, and more complex plots cannot be entirely discounted. Furthermore, those executing such attacks may be disciplined combat veterans, hardened to violence.

We assess the number of ‘die-hard’ FTFs who have actually returned to the UK to be low, and therefore the frequency or severity of attacks is unlikely to markedly change. However, an influx of such individuals would likely present a major challenge to security services, particularly in the medium-term, as controls are relaxed and resources are reallocated.

For any further questions about this report, please contact the Pool Re SOLUTIONS Risk Awareness Team at

To explore more resources from our Pool Re SOLUTIONS team, please click here.

COH_J013015 Pool Re MTU Sep web images2

08 Oct: Monthly Threat Update September 2021

There were no terrorist attacks in Great Britain this month. However, the Director General of MI5 warned that the recent withdrawal of NATO troops from Afghanistan would likely exacerbate the terrorist threat to the United Kingdom in future. He also revealed that four late stage terror plots had been interdicted since early 2020.
COH_J013000 Pool Re MTU Aug web images2

07 Sep: Monthly Threat Update August 2021

There were no confirmed terrorist attacks in the UK, Western Europe or North America in August 2021. However, a shooting by a selfdescribed ‘incel’ in Plymouth, which resulted in the deaths of five civilians and the gunman, may be reclassified as terrorism according to Devon and Cornwall police. This was the first confirmed case of incel-related violence to take place in the UK, although police have disrupted several planned attacks in recent years. 
COH_J012990 Pool Re MTU July web images2

04 Aug: Monthly Threat Update July 2021

There were no significant terrorist attacks or plots in the UK, Western Europe or North America in July 2021. However, the US and allied NATO forces began their withdrawal from Afghanistan, which is highly likely to lead to a resurgence in Al-Qaeda (AQ) operations in the country. This is likely to pose an increased threat to Western countries in future.

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