Terrorism in the United Kingdom, according to the Home Office, poses a significant threat to the state.[1] There have been various causes of terrorism in the UK. Before the 2000s, most attacks were linked to the Northern Ireland conflict (the Troubles). In the late 20th century there were also attacks by Islamic terrorist groups.
Since 1970, there have been at least 3,395 terrorist-related deaths in the UK, the highest in western Europe.[2] The vast majority of the deaths were linked to the Northern Ireland conflict and happened in Northern Ireland.[2] In mainland Great Britain, there were 430 terrorist-related deaths between 1971 and 2001. Of these, 125 deaths were linked to the Northern Ireland conflict,[3] and 305 deaths were linked to other causes,[4] including 270 in the Lockerbie bombing.[4] Since 2001, there have been almost 100 terrorist-related deaths in Great Britain.
The UK’s CONTEST strategy aims to prevent terrorism and other forms of extremism.[5] It places a responsibility on education and health bodies to report individuals who are deemed to be at risk of radicalisation.[5]: 35 The 2023 CONTEST report indicated that 75 per cent of the Security Service (MI5)'s caseload was from monitoring Islamist threats.[6] In 2023, 80% of the Counter Terrorism Police network’s live investigations were Islamist while 10% were Extreme Right-Wing.[7] In 2024, polling by YouGov found that half of the public in Great Britain believed that Islamic extremists were the biggest extremist threat. 76% considered Islamic extremists to be a “big” or “moderate" threat, although attitudes differed significantly along political lines.[8]
1,834 people were arrested in the UK from September 2001 to December 2009 in connection with terrorism, of which 422 were charged with terrorism-related offences and 237 were convicted.[9]
There have been many historically significant terrorist incidents within the United Kingdom, from the Gunpowder Plot of 1605[12][13] to the various attacks related to The Troubles of Northern Ireland. In recent history, the UK security services have focused on the threat posed by radical Islamic militant organisations within the UK, such as the cell responsible for the 7 July 2005 London bombings.
A "restricted" 12 June 2008 MI5 analysis of "several hundred individuals known to be involved in, or closely associated with, violent extremist activity" concludes that British Islamist terrorists "are a diverse collection of individuals, fitting no single demographic profile, nor do they all follow a typical pathway to violent extremism".[18] Around half were born in the United Kingdom, the majority are British nationals and the remainder, with a few exceptions, are in the country legally. Most UK terrorists are male, but women are sometimes aware of their husbands', brothers' or sons' activities. While the majority are in their early to mid-20s when they become radicalised, a small but not insignificant minority first become involved in violent extremism over the age of 30. Those over 30 are just as likely to have a wife and children as to be loners with no ties. MI5 says this challenges the idea that terrorists are young Muslim men driven by sexual frustration and lured to "martyrdom" by the promise of beautiful virgins waiting for them in paradise.[18] Those involved in Islamist terrorism have educational achievement ranging from total lack of qualifications to degree-level education. However, they are almost all employed in low-grade jobs.[18] Far from being religious zealots, a large number of those involved in terrorism do not practise their faith regularly. Many lack religious literacy and could actually be regarded as religious novices. Very few have been brought up in strongly religious households, and there is a higher than average proportion of converts. Some are involved in drug-taking, drinking alcohol and visiting prostitutes. The report claims a well-established religious identity actually protects against violent radicalisation, while the influence of clerics in radicalising Islamist terrorists has reduced in recent years.[18]
On 22 May 2017, 23 people were killed after a bombing occurred following a concert by Ariana Grande in the most deadly terrorist attack on British soil since 2005.[20] After a COBRA meeting, UK Prime Minister Theresa May announced that the UK's terror threat level was being raised to 'critical', its highest level.[21] By raising the threat level to "critical", Operation Temperer was started, allowing 5,000 soldiers to replace armed police in protecting parts of the country.[22][23] BBC's Frank Gardner said that the first deployment of troops is expected to be in the hundreds.[24]
There have been calls for the publication of a report into the finance of terrorism which the government said they left unpublished for security reasons. Tim Farron said, "Theresa May should be ashamed of the way she has dragged her heels on this issue, first as home secretary and now as prime minister. No amount of trade with dodgy regimes such as Saudi Arabia is worth putting the safety of the British public at risk, and if May is serious about our security, she would publish the report in full, immediately."[25]
From June 2016 to June 2017, 379 people in the UK had been arrested for terrorism-linked offences with 123 of them being charged, 105 of them for terrorism offences. This was a 68% increase from the previous year which was partly due to various Islamist terror attacks on UK soil such as the Manchester bombing, the London Bridge attack, and the Westminster attack. The report also said that 19 terrorist plots had been foiled by British police since June 2013.[26]
Jihadist material including bomb making instructions and execution videos gets more clicks in the UK than in any other European nation and is spread among a wide range of different domains. Internet companies have been accused of not preventing this. New measures are being considered to stop internet providers from showing this type of content including fines for internet companies that do not remove jihadist material. David Petraeus said the Parsons Green bomb could have been made from online instructions. Petraeus noted the technical and other skill of the terrorist websites and added, "It is clear that our counter-extremism efforts and other initiatives to combat extremism online have, until now, been inadequate. There is no doubting the urgency of this matter. The status quo clearly is unacceptable."[27]
Police chief, Sara Thornton fears cuts to the police budget will weaken counter terrorism. Thornton maintains resources needed to deal with terrorist incidents are brought from mainstream policing adding to the strain on general policing. Thornton maintains neighbourhood policing is important because it gives people confidence in the police. Then confident people give the police information needed to prevent terrorist attacks. Thornton said, "Fewer officers and police community support officers will cut off the intelligence that is so crucial to preventing attacks. Withdrawal from communities risks undermining their trust in us at a time when we need people to have the confidence to share information with us." Thornton also said, "Experts tell us that the spate of attacks in the UK and Europe are a shift not a spike in the threat, which will take 20 or 30 years to eliminate. This new normality necessitates an open-minded dialogue with government about how we respond; and our resources have got to be part of the conversation."[28][29]
The British government has designated 58 organisations as terrorist and banned them. 44 of these organisations were banned under the Terrorism Act of 2000. Two of these were also banned under the Terrorism Act of 2006 for "glorifying terrorism." Other than the far-right neo-Nazi National Action, the other fourteen organisations operate (for the most part) in Northern Ireland, and were banned under previous legislation.[1] However the increase to 10%, from a base of 6%, made far-right terrorism the fastest growing threat. Other than caseloads, there have also been an increasing number of arrests, referrals and terror plots.[30]
Organisations the government has designated as terrorist and banned are:[1]
According to political scientist Gilles Kepel, the jihadi violence is rooted in Islamic fundamentalism in the form of Salafism, an ideology that clashes with the values of Western democracies and which entered the United Kingdom when the country gave shelter to radical Islamist leaders from around the world in London.[31] According to Kepel, an individual progresses into violence by first becoming a salafist. Further, he states that salafist ideology has led to attacking targets which symbolizes Western culture, such as the concerts at Manchester and in the Bataclan theater or deliberately timing attacks to interfere with democratic elections.[31] Scholar Olivier Roy disagrees, saying that the majority of Islamic terrorists are radicals first and are drawn to fundamentalist Islam as a result.[32] He has argued that there's no evidence that they go from Salafism to terrorism, noting that Islamic terrorist Abdelhamid Abaaoud was known to violate religious rules about halal food.[33] Roy has also argued that the burkini bans and secularist policies of France provoked religious violence in France, to which Kepel responded that Britain has no such policies and still suffered several jihadist attacks in 2017.[31]
In the 2000s, there was an increase in the number of British Pakistanis traveling to training camps in the Pashtun regions of Pakistan to join al-Qaeda and other jihadist groups. The British government received early warnings of this radicalization trend among British Muslims in March 2004, when security authorities foiled the "fertilizer bomb plot" orchestrated by a cell of jihadists of Pakistani origin. The most significant event illustrating this trend was the 7 July 2005 London bombings, a series of suicide bombings in the London Underground which resulted in fifty-two deaths and over seven hundred injuries. The perpetrators had been trained in an al-Qaeda camp on the Pakistani side of the Afghan–Pakistani border.[34]
In July 2017, it was reported that British authorities had stripped some 150 suspected criminals with dual citizenship of their British passport, to prevent them from returning to the UK. Those deprived of their UK citizenship included both "jihadis" and "jihadi brides".[35]
In October 2020, Islamist terrorism remained the greatest threat to the UK by volume according to Ken McCallum, the Director General of MI5.[36] A report published in the same year found that of the 43,000 extremists on MI5's watchlist, around nine-tenths of the people on the list are Islamist extremists.[37] In July 2023, Suella Braverman, the Home Secretary of the United Kingdom, reiterated that Islamic terrorism was the primary domestic threat facing the UK.[38] Islamic terrorism represented 67% of attacks since 2018, 75% of MI5's caseload, and 64% of those in custody for terrorism-connected offences according to the 2023 CONTEST report.[6] The Independent Reviewer for the government's anti-terror programme, Sir William Shawcross, has stated that there was a reluctance to investigate Islamist threats due to fears of being labelled Islamophobic or racist. Instead, staff from the government's anti-terror programme were biased towards tackling far-right threats despite Islamist threats posing a greater risk.[39] His investigation found that 80% of the Counter Terrorism Police network’s live investigations were Islamist while 10% were Extreme Right-Wing. However, Shawcross found that the majority (51%) of referrals were for mixed, unstable or unclear (MUU) ideology concerns, followed by extreme right-wing ideology at 25%, and Islamist related radicalisation made up only 22% of referrals.[7]
In October 2024, Ken McCallum indicated that the terrorist threat trend he was most concerned about was the worsening threat from Al-Qaeda and in particular from Islamic State. Roughly 75% of counter terrorist work remained from Islamist threats, although he highlighted that threats were becoming more sophisticated with people consuming both Extreme Right Wing and Islamist extremist instructional material. Lone individuals radicalised online made up the majority of threats.[40][41]
^"PM Theresa May raises UK threat level to 'critical'". ITV News. 23 May 2017. Retrieved 23 May 2017. Raising the level to critical means that military personnel could be deployed to support armed police officers - part of a plan known as Operation Temperer.
^"'That Ignoramus': 2 French Scholars of Radical Islam Turn Bitter Rivals". Retrieved 2018-07-19. 'There is no proof that shows the young men go from Salafism to terrorism,' Mr. Roy said, pointing out that the planner of the Paris attacks in November, Abdelhamid Abaaoud, ate McDonald's, which is not halal. 'None of the terrorists were Salafists.'
^Steinberg, Guido (2013). "Unlikely Internationalists: Putting German Jihadism into Perspective". German Jihad: On the Internationalization of Islamist Terrorism. Columbia studies in terrorism and irregular warfare. New York, NY: Columbia University Press. pp. 27–28. ISBN978-0-231-50053-1.
Staniforth, Andrew, and Fraser Sampson, eds. The Routledge companion to UK counter-terrorism (Routledge, 2012).
Sinclair, Georgina. "Confronting terrorism: British Experiences past and present." Crime, Histoire & Sociétés/Crime, History & Societies 18.2 (2014): 117-122. online
Tinnes, Judith, ed. "Bibliography: Northern Ireland conflict (the troubles)." Perspectives on Terrorism 10.1 (2016): 83-110. online
Walker, Clive, The Anti-Terrorism Legislation (Third edition, Oxford University Press, 2014)