British prime minister Margaret Thatcher warned there were times when Northern Ireland made her "berserk", such was the sheer savagery of the violence.
Secret documents revealed the Conservative Party leader admitted that watching the footage of two British army corporals accidentally driving into a Republican funeral cortège in Belfast, before being dragged from their vehicle, beaten, stripped and then executed, was shocking.
Reports released as part of the 1988 State Archive indicated Ms Thatcher was horrified by what she witnessed.
"Those two corporals were among the worst things in my life," she told Taoiseach Charles Haughey in 1988. "The savagery was unbelievable - and don't think the people who did it were contrite. Not the least bit."
In March 1988, Corporals Derek Wood and David Howes accidentally drove into the funeral cortège of Caoimhin MacBradaigh, who had been killed by Michael Stone during his notorious attack on mourners at the Gibraltar Three funerals at Milltown Cemetery.
The soldiers were not aware of the funeral route - and their car was blocked and then surrounded. Corporal Wood drew his service pistol and fired a shot into the air.
However, the two soldiers were overpowered, dragged from the car, beaten and then driven away from the scene. They were stripped and then executed by an IRA unit.
Three months later, the IRA detonated a Semtex bomb by a vehicle used by off-duty British soldiers involved in a Lisburn fun run, killing six.
In a letter to Mr Haughey, Ms Thatcher said she appreciated Government sympathy but wanted greater intelligence-sharing. "As we both know from recent experience, the Provisional IRA has developed over the years into a very dangerous organisation and the concentration of terrorists in Northern Ireland is now one of the biggest in the world."
Separately, Government officials were warned by British politicians to be very careful with interventions over the killing of three IRA volunteers in Gibraltar by the SAS, lest the British public perceive Dublin to be condoning terrorism.
The three IRA volunteers - Mairead Farrell, Daniel McCann and Sean Savage - were shot dead on March 6, 1988, in Gibraltar as part of Britain's Operation Flavius.
All three IRA volunteers were unarmed and no explosives were found in the car they had driven across the border from Spain.