MI5 - Security Service


What is terrorism?

Aftermath of the 1996 Manchester bombing.

Terrorism presents a serious and sustained threat to the United Kingdom and UK interests abroad. Terrorist groups seek to cause widespread disruption, fear and intimidation. They use violence or the threat of violence as a means of publicising their causes, motivating those who might be sympathetic to them and intimidating those who do not sympathise. They often aim to influence government policies and they often reject existing democratic processes, or even democracy itself, as a means of achieving their objectives. Although there is no generally agreed definition of terrorism internationally, in the UK the Terrorism Act 2000 defines terrorism as:

"The use or threat of action designed to influence the government or an international governmental organisation or to intimidate the public, or a section of the public; made for the purposes of advancing a political, religious, racial or ideological cause; and it involves or causes:

  • serious violence against a person;
  • serious damage to a property;
  • a threat to a person's life;
  • a serious risk to the health and safety of the public; or
  • serious interference with or disruption to an electronic system."

The different terrorist threats

International terrorism

International terrorism from groups such as Al Qaida presents a threat on a scale not previously encountered. Drawing on extremist messages presented by figures such as Usama bin Laden, Al Qaida and its related networks seek to carry out terrorist attacks around the world, aiming to carry out "high impact" attacks causing mass civilian casualties.

Northern Ireland-related terrorism

Northern Ireland-related terrorism continues to pose a serious threat to British interests. Although a peace process has been active for several years, some Republican terrorist groups oppose the peace process and continue to attack economic and political targets.

Domestic extremism

Other domestic extremist groups may aspire to campaigns of violence but lack developed terrorist capabilities. For the most part, they pose a threat to public order but not to national security.

Protecting your business

For detailed guidance on how to protect your business from the threat of terrorism, please see the website of the Centre for the Protection of National Infrastructure (CPNI) Links to an external website.

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