Former Taoiseach Charles Haughey urged security forces north and south to combine to bring the Enniskillen Remembrance Day bombers to justice.
The minutes of an extraordinary meeting of the Anglo-Irish Intergovernmental Conference on cross-border security cooperation in the wake of the atrocity are among declassified files released in Belfast.
The meeting in Dublin on November 16 1987 was attended, on the British side, by Secretary of State Tom King and his junior minister John Stanley and, on the Irish side, by the Minister for Foreign Affairs Brian Lenihan and Gerry Collins, Minister for Justice.
The respective chiefs of police from both sides of the border, Sir John Hermon (RUC) and Eamonn Doherty (Garda) were also in attendance.
In his personal message to the British Prime Minister Margaret Thatcher in the wake of the IRA attack, which left 11 dead and 63 wounded, Mr Haughey said that "all the security forces in this island must combine ... to have the perpetrators brought to justice".
The British asked for the meeting for three reasons: the Remembrance Day bomb, the kidnapping of dentist John O'Grady by a criminal gang, and the Eksund arms shipment when French customs seized a Panamanian-registered coaster off the French coast containing 120 tons of sophisticated weaponry.
This was a matter of grave concern, not only because of the size of the cargo but because of indications that there had been earlier shipments of arms. They faced "a situation of extreme gravity". The Provisional IRA would be in a defiant mood following Enniskillen and would be all the more dangerous.
Responding, Mr Collins agreed that the threat posed by the reported arms shipments was a frightening one. The problem was too large for any government and the Irish would be looking for help from other quarters in dealing with it.
Referring to Enniskillen, Mr King described it as a shock to the system. He did not see the outrage as a last desperate throw by the IRA, but rather as a natural outcome of their increased delegation of operational decisions to autonomous cells.
Turning to the O'Grady kidnapping, Mr Collins explained that the Garda operation had had to be conducted with caution because of the known propensity of Dessie O'Hare's gang for viciousness. Mr O'Grady had been freed and no ransom had been paid.
The RUC Chief Constable, Sir John Hermon, said in relation to the arms shipments that there were indications of hides being prepared in the north.
He shared Mr Collins' concern about Semtex which was suitable for small but dangerous anti-personnel grenades. For the British, Mr Stanley noted that it was unsafe to assume that the Libyans would cease to make arms available to PIRA. He offered the British help with the search for arms in the Republic.
Summing up, Mr Lenihan described it "as a time for cracking down on terrorism".
