The Troubles in Northern Ireland from 1969 had led to extra security costs for the State of an estimated £2.5 billion (€3.175 billion) by 1994, according to internal Department of Foreign Affairs correspondence dating from the time.
In a briefing prepared by the security section of the department, it was also estimated that security costs were running at £200 million per annum.
The briefing was prepared by officials ahead of the IRA ceasefire, which was announced in August 1994.
It noted that 3,100 people had been killed during the Troubles and more than 30,000 injured. Thirty-two people had been killed in the first months of 1994.
Apart from the human cost, the cumulative financial cost of the violence to both the Irish and UK government since 1969 was estimated to be about £20 billion, it stated.
“The cost to the State of extra security measures arising from the violence in Northern Ireland since 1969 is of the order of £2.5 billion. The cost is running annually at more than £200 million.
“The Irish taxpayer has to spend up to three times more per capita on security than his British counterpart as a result of the continuing violence in Northern Ireland . A third of the defence budget is estimated to be spent on NI-related security.”
The briefing also mentioned a recent economic report that had estimated Northern Ireland had lost 46,000 jobs between 1973 and 1990 as a consequence of decisions by foreign companies not to invest there.
The information is contained in confidential documents from the Department of Foreign Affair from 1991 to 1998 that have been transferred to the National Archive and which will be available for public viewing from January. (Archive ref: 2021/50/365)
