The Internal Security Unit (ISU) was the name given to the counter-intelligence

Counter-intelligence

Counterintelligence or counter-intelligence refers to efforts made by intelligence organizations to prevent hostile or enemy intelligence organizations from successfully gathering and collecting intelligence against them. National intelligence programs, and, by extension, the overall defenses of...

 and interrogation unit of the Provisional Irish Republican Army

Provisional Irish Republican Army

The Provisional Irish Republican Army is an Irish republican paramilitary organisation whose aim was to remove Northern Ireland from the United Kingdom and bring about a socialist republic within a united Ireland by force of arms and political persuasion...

 (IRA). This unit was often referred to as the Nutting Squad.

The unit is thought to have had jurisdiction over both Northern

IRA Northern Command

Northern Command was a command division in the Irish Republican Army and Provisional IRA, responsible for directing IRA operations in the northern part of Ireland.-IRA:...

 and Southern Command of the IRA, (encompassing the whole of Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

), and to have been directly attached to IRA General Headquarters (GHQ).

Duties of the ISU

The group was believed to have had a number of briefs:

1. Security and character vetting of new recruits to the IRA,
2. Collecting and collating material on failed and compromised IRA operations,
3. Collecting and collating material on suspect or compromised individuals (informers),
4. Interrogation and debriefing of suspects and compromised individuals,
5. Carrying out killings of those judged guilty by IRA courts martial.

The ISU was believed to have unlimited access to the members, apparatus, and resources of the IRA in carrying out its duties. Its remit could not be countermanded except by order of the Army Council

IRA Army Council

The IRA Army Council was the decision-making body of the Provisional Irish Republican Army, more commonly known as the IRA, a paramilitary group dedicated to bringing about the end of the Union between Northern Ireland and the rest of the United Kingdom. The council had seven members, said by the...

.

Depositions obtained as part of its operation would ideally be noted on paper, and if possible recorded for the purposes of propaganda.

Examples of ISU activity

• Debriefing of IRA volunteer
  Volunteer (Irish republican)
  Volunteer, often abbreviated Vol., is a term used by a number of Irish republican paramilitary organisations to describe their members. Among these have been the various forms of the Irish Republican Army and the Irish National Liberation Army...
  
  s following their detention by security forces operating in Northern Ireland. These interviews would take place to discover if a volunteer had flipped and decided to betray information or secrets of the organisation. They would also take place in the event of an operation, weapons cache, or unit being exposed to danger or uncovered.
• Involvement in the Court Martial process as detailed in the IRA manual, The Green Book
  The Green Book (IRA training manual)
  The IRA Green Book is a training and induction manual issued by the Irish Republican Army to new volunteers. It was used by the post-Irish Civil War Irish Republican Army and Cumann na mBan, , along with offspring groupings such as the Provisional IRA...
  
  .
• The membership of the IRA and wider republican community are expected to comply with requests for information made by the ISU, this information then being used to build or demolish accusations made against an IRA volunteer.

Further information/sources

• Ingram, Martin with Harkin, Greg "Stakeknife". Britain's secret agents in Ireland." O'Brien Press, 2004.

External links

• "It's time ordinary republicans stopped being led like sheep" - Ingram interview with the Sunday Tribune, 19 February 2006.
• Lengthy Interview given by Martin Ingram on Radio Free Eireann describing his FRU activities. NOTE, the interview begins twenty-five minutes in.