It’s more than 40 years since Margaret Thatcher insisted that the North’s republican prisoners be treated as criminals rather than as political prisoners.
Her self-righteousness and wilful ignorance had immediate consequences.
The IRA secured a propaganda victory and welcomed a wave of recruits who saw no potential politics.
A new round of violence and all the enduring bitterness and mistrust that provoked began. Big-stick politics, as they nearly always do, failed.
Inevitable peace talks were again put out of immediate reach. Many lives were lost before negotiation replaced confrontation.
More than four decades later we live with the toxic legacy of that over-reach and profound lack of empathy.
The lessons of that episode are as relevant as ever, especially as they have been resharpened by President Trump’s decision to withdraw America from the Iran nuclear agreement.
The decision sunders years of diplomacy and plunges the Middle East into even deeper uncertainty.
Just as Thatcher’s miscalculation was a catalyst for renewed terror Trump’s U-turn has been celebrated by Iran’s hardliners.
The Revolutionary Guards “congratulated” the nation on the decision. MPs burnt an American flag and the text of the 2015 landmark deal in the country’s parliament on Wednesday.
Just as Thatcher revived the Provo terrorists, Trump has rejuvenated the bigoted, homophobic, misogynist, deeply anti-Western Revolutionary Guards. Moderates and potential reformers can only look on in despair.
Whether the insistence by the other deal signatories — France, China, Britain, Russia, and Germany — that it “is not dead” is realistic remains to be seen but the aspiration of encouraging Iran to eventually become a reliable member of the international community has been dealt a severe blow.
European leaders are determined to try to salvage the deal though this sets them on a collision course with Mr Trump’s America, an increasingly volatile and disconnected player in today’s world.
The suggestion that US national security adviser John Bolton has warned that European companies doing business in Iran must stop doing so within six months or face sanctions adds a sinister layer to the episode.
Does America really think it can dictate the foreign policy of countries it does business with? This threat rings loudly in Ireland as we have invested considerable time and effort in trying to establish a market for Irish farm produce in Iran. Does Mr Bolton expect the EU to dance to his tune too?
Despite all of that Mr Trump is right about his core objective — Iran cannot be allowed develop nuclear capabilities.
This non-negotiable is also the core objective of the deal he abandoned, one most neutral observers — and his security advisors — believe Iran has honoured.
That may or may not be the case but it is difficult to see how Mr Trump can dismiss Iran but embrace North Korea in a seperate round of nuclear negotiations.
At this remove, one rogue state looks pretty much like the other and America seems at best inconsistent.
All those years ago Thatcher’s grave error guaranteed the near-permanent dominance of extremism and, tragically, Mr Trump seems to have fallen into the very same trap.