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Ireland suppresses terrorism under longstanding criminal law and dedicated legislation: the 1998 Offences against the State (Amendment) Act and the 2005 Criminal Justice (Terrorist Offences) Act. Terrorism pertains to certain crimes committed in order to seriously intimidate the population, unduly compel conduct by a government, or destroy the fundamental political, constitutional, economic, or social structures of a State.

Compliance with International Law:
Last updated: one year ago

The Definition of Terrorism in Domestic Law

Under its 2005 Criminal Justice (Terrorist Offences) Act, Ireland defines "terrorist activity" as:

an act that is committed in or outside the State and that—

(a) if committed in the State, would constitute an offence [set out in the Act, including offences of violence and criminal damage], and

(b) is committed with the intention of—
(i) seriously intimidating a population,
(ii) unduly compelling a government or an international organisation to perform or abstain from performing an act, or
(iii) seriously destabilising or destroying the fundamental political, constitutional, economic or social structures of a State or an international organisation.S. 4, 2005 Criminal Justice (Terrorist Offences) Act.  

The predicate offences include violence against the person, criminal damage, as well as "maliciously obstructing railways". There is no explicit exception for the exercise of fundamental human rights and freedoms, although Section 6(5) of the 2005 Act clarifies that engaging in protest, advocacy, or dissent is not "of itself" a sufficient basis for inferring that the person is carrying out an act within the definition of “terrorist activity”.

Section 18 of the 1939 Offences against the State Acts defines “unlawful organisations” as inter alia those which engage or promote treason or violence or attempt to raise military force in contravention of the Constitution. Section 21(1) makes it unlawful to be a member of such organisation. Under Section 19, the Government is permitted to suppress any organisation that it deems to be unlawful. 

Section 5(1) of The Criminal Justice (Terrorist Offences) Act 2005 defines a “terrorist group” as a group that “engages in, promotes, encourages or advocates the commission, in or outside the State, of a terrorist activity" (and is an unlawful organisation within the meaning of the 1939 Offences against the State Acts). Section 5(4) affirms that this definition applies whether the terrorist group is based in or outside the State.

Adherence to Global and Regional Terrorism Treaties


Ireland is a State Party to all of the major United Nations treaties on terrorism.

Adherence to Global Terrorism Treaties
Treaty Adherence
1973 Convention on Crimes against Internationally Protected Persons State Party
1979 Hostage-Taking Convention State Party
1997 Terrorist Bombings Convention State Party
1999 Terrorist Financing Convention State Party
2005 Nuclear Terrorism Convention Signatory


Ireland is a State Party to only one of the major European treaties on terrorism.


Adherence to Regional Terrorism Treaties
Treaty Adherence
1977 European Convention on the Suppression of Terrorism State Party
2003 Protocol amending the European Convention on the Suppression of Terrorism Signatory
2005 Convention on the Prevention of Terrorism Signatory
2015 Additional Protocol to the Convention on the Prevention of Terrorism State not party

Laws and Penalties for Terrorist Offences

Section 6(1) of The Criminal Justice (Terrorist Offences) Act 2005 makes it a criminal offence for a person to engage, attempt to engage, or make a threat to engage, in terrorist activity or terrorist-linked activity.  

Under Section 7 of the 2005 Act, a person found to be guilty of a terrorist offence is liable to be punished according to the gravity of the offence up to life imprisonment. 

Section 3 of the 1976 Criminal Law Act makes it an offence to recruit another person to join an unlawful organisation subject to a term of imprisonment not exceeding ten years. 

The Offences against the State (Amendment) Act 1998, which was enacted in the aftermath of the Omagh bombing, amends the Offences against the State Acts 1939-1985, the State’s main body of counterterrorist legislation, and created new substantive offences.

The death penalty was abolished in full in the Republic of Ireland by the 1990 Criminal Justice Act.

It is questioned whether the continued operation of the Special Criminal Court in the Republic of Ireland is compatible with the State’s international human rights obligations. Under Article 38(1) of the Constitution of the Republic of Ireland and in accordance with Article 6 of the European Convention on Human Rights, Ireland recognises a right to a fair trial. The Special Criminal Court, which was created as a temporary and emergency response to the terrorist threats emanating from the troubles in Northern Ireland, does not include a jury in the trial and is presided over by three judges.

Counterterrorism Capacities and Policies at Domestic Level

The Garda Síochána, the Irish police and security service, has a National Crime and Security Intelligence Service whose task is to identify and analyse the threat to the State from terrorists (and organised criminal gangs). 

The Garda Counter-Terrorism International (CTI) unit comprises some 30 specialist officers. In 2016, detectives from the Garda CTI assisted with the investigation into the 2015 Sousse terrorist attacks in Tunisia where 3 Irish citizens were killed.


Ireland 2005 Criminal Justice (Terrorist Offences) Act

Ireland 1939 Offences against the State Acts

1998 Offences against the State (Amendment) Act