Terrorism is a major threat for businesses. Terrorist groups may seek to cause harm to the economy as a whole by attacking business premises or they may seek to attack specific businesses to advance their political agendas. The threat is not confined to the UK; companies that do business overseas may also be targeted.
The most significant terrorist threat comes from Islamist terrorism with its ambitions to mount high impact attacks designed to result in mass casualties.
The current threat level from terrorism for the UK is SUBSTANTIAL, 'an attack is likely'.
Information on threat levels can be found on the Security Service (MI5) website and on GOV.UK.
Improvised Explosive Devices (IEDs)
These can be delivered to their targets in vehicles, by post or by a person. Car bombs were frequently used by the IRA during the Troubles in Northern Ireland. Islamist terrorist groups often use suicide operatives in vehicles to improve the likelihood of the explosives detonating at the required moment, and suicide bombers also carry explosive devices into the vicinity of a target individual or location. Notable examples of this include the Manchester Arena attack in 2017 and the Easter Bombings in Sri Lanka in 2019.
Dissident republican groups in Northern Ireland continue to use a range of explosive devices, including under-vehicle devices, pipe bombs and postal explosive devices.
Shootings and close quarter attacks
Islamist terrorist groups have orchestrated a number of shootings and close quarter attacks targeting Westerners, in the Middle East, North Africa and Europe.
Notable examples include in June 2015 when Daesh claimed responsibility for an attack on the Port El-Kantoui tourist resort in Sousse, Tunisia which killed 38 people, including 30 British nationals and November 2015, when a terrorist cell conducted a series of coordinated attacks in Paris, using firearms and suicide bombs, killing 130 people and injuring 368 more. This was the most sophisticated western attack carried out by Daesh, involving at least nine operatives and using multiple weapons including automatic firearms and person-borne improvised explosive devices (PBIEDs).
The use of firearms is also a popular methodology of extreme right-wing terrorists. Notable attacks using firearms include the Christchurch Mosque Shootings in March 2019.
More recently the London Bridge and Westminster attacks in 2017 illustrate the threat from close quarter bladed weapon attacks.
Dissident republican groups have also used firearms in their attacks against the security forces in Northern Ireland. These have included the murders of Sappers Mark Quinsey and Patrick Azimkar outside Massereene Barracks in 2009, Constable Stephen Carroll in 2009, and prison officer David Black near Lurgan in November 2012.
Kidnappings
Islamist groups in conflict zones around the world actively seek to kidnap Western nationals for financial and propaganda gain. In the latter half of 2014, Daesh released videos claiming to show the murders of, amongst others, UK nationals David Haines and Alan Henning. Through these, Daesh hoped to spread fear and attempted to show its strength over the West.
As well as in Syria and Iraq, the kidnap threat persists in Yemen and parts of the West, North and East Africa where Islamist groups are active.
Chemical, biological and radiological (CBR) devices
To date, no such attacks have taken place in the UK. Alternative methods of attack, such as explosive devices, are more reliable, safer and easier for terrorists to acquire or use. Nevertheless, it is possible that Al Qaida, Daesh, or other terrorist groups may seek to use chemical, biological or radiological material against the West.
In addition to physical attack methods, terrorists may also try to access information that may be of use to them. For example, they may try to radicalise an individual within an organisation who can provide "inside" information that helps to plan an attack.