Taoiseach Dr Garret FitzGerald's immediate condemnation of the IRA's Brighton hotel bombing and his personal condolences to the victims dramatically helped ease Anglo-Irish relations.
Files revealed Dr FitzGerald's comments about the bombing had a significant impact on public opinion in the UK.
The 20lb bomb, set off via a long-delay timer, wrecked the Grand Hotel in Brighton on October 12, 1984, during the Conservative Party conference. Prime Minister Margaret Thatcher and her Cabinet narrowly avoided being killed.
Five people died and 34 others were left badly injured. Two senior Conservative Party officials were among the dead while Margaret Tebbit, the wife of Board of Trade chairman, Norman Tebbit, was left permanently disabled.
Department of the Taoiseach papers reveal how many British people appreciated Dr FitzGerald's swift condemnation of the atrocity.
Keith Vaughan, a member of the Crawley Conservative Association and a steward at the conference, wrote to Dr FitzGerald on October 24 saying how much his comments meant.
"Your prompt words of condolence and support after the terrible tragedy in Brighton are appreciated very much," he said.