Two years after declaring a ceasefire in 1972, the Official IRA leadership was still contemplating the overthrow of the governments of Northern Ireland and the Republic.
In 1974, it produced a manual for its intelligence officers entitled A Reporter's Guide to Ireland, which set out ways to prepare for a terrorist campaign and to subvert government and security structures.
The document shows the Official IRA was well read on the latest anti-terrorist policies and suspected the British military and secret service of using academic and social services organisations in Northern Ireland as fronts for intelligence-gathering.
It had also infiltrated the British military and seized highly restricted documents, some reprinted in its manual, which contains extensive excerpts from British army intelligence guidance documents the group had "seized".
In several instances, the manual shows the Officials, despite their ceasefire, intent on pursuing a subversive/terrorist campaign to undermine and overthrow the government apparatus on both sides of the Border.
History since the drawing up of the document shows that while it contains highly advanced thinking on the conduct of a subversive campaign, the group's analysis of political developments, North and South, was very flawed.
But its analysis of the existing political structures and parties appears over-optimistic in its belief that internal disputes would fatally split Fianna Fail, the Labour Party and the SDLP.
It also completely underestimated the strength of the Provisional IRA, saying in 1974 it was in "decline".
In fact, the Officials declined swiftly after the document was drawn up, with the Seamus Costello grouping leaving shortly afterwards to form the Irish National Liberation Army.
It is likely that Costello and former Official IRA chief-of-staff, Cathal Goulding, who died last month, both had a hand in drawing up the Guide.
According to republican sources, the Official IRA still exists and has arms but only a handful of members.
Its political wing developed from the Republican Clubs to the Workers' Party.
The majority of the political group split from the Workers' Party in 1994 to form Democratic Left, which last week merged with the Labour Party.
Ironically, while the Officials were sworn opponents of the Provisionals, it appears their own subversive education manual may have helped the Provos to reorganise after severe setbacks in the 1970s.
By the late 1970s, the Provisionals re-emerged, under the Northern leadership that largely exists to this day, as one of the most advanced "terrorist" groups in modern history.
The Official IRA manual includes an extensive analysis of new and increasingly successful interrogation techniques used by the British army and RUC in the North and sets out guidelines for foiling these techniques.
These anti-interrogation techniques were copied almost verbatim in later Provisional IRA manuals.
The Guide's introduction describes the importance of intelligence gathering and "counterintelligence" - how to limit the "enemy's" efforts to penetrate the IRA. The lessons on "counter-intelligence" seem to be based on material seized from the British military.
British military documents reprinted in the manual include British Army Training for Interrogators, which sets out ways of selecting and eliciting information from prisoners.
In seizing this document, the Official IRA could analyse the techniques and devise counter-techniques to reduce the chances of prisoners "breaking" and giving information.
The seizure of such a document, unknown until now, was a major intelligence coup, although the Provos probably benefited most from it.
The manual displays the Official IRA's hostility to what it terms the "26-county government" and urges intelligence officers to infiltrate and recruit members of the Defence Forces or Garda Siochana.
It states: ". . . all IOs [intelligence officers] in the South should carry out the same military intelligence as their counterparts in the North but they should also try to establish as many contacts in the forces as is possible and attempt to establish just how far such people are prepared to go to help the movement win its objectives."
It adds: "It should be clearly stated here that there is no intention of attacking as such 26-county military installations. Contact with such personnel should be maintained at frequent intervals and in the strictest security."
But in 1974 the Officials clearly viewed the British army as its main enemy. The Guide states: "The current role of the British army is not simply to maintain `law and order' but to gather information on all revolutionary organisations in Ireland . . .
"In this light the Republican Movement is seen as a much greater danger than say the Provisionals - in the long term - because we are committed to the overthrow of all that the army is paid to protect."