In a desperate sign of the gravity of the crisis, Mr FitzGerald — who had taken office only days beforehand — warned that Ireland’s democracy was seriously under threat while relations with Britain were plunging to dangerous depths.
And in an attempt to win over support from the US leader, he assured Mr Reagan that he could play a decisive role in ending the IRA prisoner fast.
While it was early in the leaderships of both Mr Reagan and British prime minister Mrs Thatcher, the pair would go on to be considered political soulmates during the West’s cold war tensions with the Soviets.
The letter, dated July 1981, was drafted after six prisoners had already died and the Irish government was on tenterhooks over the imminent death of Kieran Doherty, who had been elected TD for Cavan-Monaghan.
Admitting he hesitated about imposing on the US president — who had survived an assassination attempt only a few months previously — Mr FitzGerald said it was his duty to seek the cooperation of “the leader of the greatest democracy on earth”.
“I would ask you to use your enormous influence with the British prime minister within the next 24 hours in the interest of averting a death which would inevitably increase support for the terrorists and further undermine the stability of our democracy in a dangerous way and can only harm the interests of the British, Irish and American governments,” he wrote.
“I believe that an expression of your concern to Mrs Thatcher of the deterioration in the state of opinion among Americans of Irish extraction and among many other Americans and of the urgent necessity to avert the consequences which would result from Mr Doherty’s death could be of decisive importance.”
Mr FitzGerald said Ireland was facing a desperate crisis in the fight against support for terrorism, which he said was at an all-time high, particularly from America.
Mr FitzGerald said the British government was “understandably concerned” not to make concessions to IRA inmates, which would give them a privileged status or cede control of prisons.
The ex-taoiseach wrote that he “would be most grateful if you could consider using your good offices with prime minister Thatcher” to pressure the British into accepting the understanding mediated by the Irish Commission for Justice and Peace before the death of Mr Doherty and “its very dangerous consequences”.
State files also show that some weeks later US senator Ted Kennedy and 17 colleagues wrote to Mr Reagan, seeking a meeting about the impact of the hunger strikes.
Mr Doherty died on August 2, on the 73rd day of his hunger strike, aged 25.