Fintan O’Toole is a celebrated Irish Times columnist whose pronouncements on Britain’s decision to leave the European Union are divisive even by the standards of the UK’s own Brexit dialogue.

For those who don’t follow his strictures, the following headlines on some of his more recent pieces will provide a flavour of the man:

“Boris has destroyed what is left of UK’s credibility”

“For the first time since 1171, Ireland is more powerful than Britain”

“British politics this week like the mad scenes in King Lear”

“Welcome to the United Kingdom of Absurdistan”

O’Toole enjoys considerable prestige in Dublin, where his reputation is that of a public intellectual and man of letters as much as controversialist. But he is also widely read in Northern Ireland, where the respect he is accorded by Remainers is mirrored almost exactly by the contempt he induces in Leavers and loyalists. But just as significant is the influence he wields in the United States, where, in addition to the learned essays he writes for the New York Review of Books, he is a regular contributor on radio and television, increasingly on the politics of Brexit.

Never mind Brussels. When O’Toole ridicules Britain and warns of the dire consequences for Ireland of a hard or No-Deal Brexit, Washington is listening.

In his latest column, published in the Irish Times on Tuesday under the snappy headline, “Tories must grasp the profound stupidity of their approach to the North”, the punditry is preceded by a reference to Theresa May’s original 2017 Brexit plan, which recognised that Northern Ireland’s “particular circumstances” presented “a range of particular challenges” to be taken into account when negotiating with Brussels. Also recalled is a letter signed jointly by the DUP leader Arlene Foster and the late Martin McGuinness of Sinn Fein two months after the EU referendum in which they stressed that Northern Ireland was “unique” and demanded of the prime minister that she be aware of the “unique aspects of negotiations that arise from the Border”.

And so to the meat of this latest polemic.

“But the result of the 2017 election created a toxic collusion in which the DUP, drunk on the illusion of power, spun the fantasy that Brexit could be exactly the same for Northern Ireland as for Somerset or Warwickshire, and May (against her better judgement) indulged it. Out went “particular” and “unique”; in came “exactly the same”. More than two years have been wasted on the pursuit of a proposition that both the British government and the DUP knew to be unreal. But in the manual of Brexit for slow learners, the last chapter of this volume was always going to be the same as the first: go back to the plain truth that Northern Ireland is unique and that, if it really has to endure Brexit, it must have a bespoke version. Its Brexit suit cannot be off the peg – it must be made to measure.”

Today, with Brexit in the balance and the DUP considering its position, O’Toole has surely hit the nail on the head. The DUP is not the same thing as Northern Ireland, and Northern Ireland is not the same as Somerset or Warwickshire. Half the electorate votes for Sinn Fein and Remain won the referendum in NI by 56 per cent to 44 per cent. If Boris Johnson genuinely hopes to conclude a deal with the EU, he has to accept that Northern Ireland must remain, in essence, within the European Customs Union, keeping the border open, ensuring frictionless trade and denying the IRA and loyalist paramilitaries the excuse to revive the armed struggle.

It is not as if close alignment with the EU lessens NI’s status as a province of the United Kingdom. As I argue in a chapter I wrote for Brexit and Northern Ireland – Bordering on Confusion? – published this month by Bite-Sized Books, Northern Ireland would still be governed by Westminster, to which it would elect 17 MPs.

“Pensions would stay the same, as would access to the NHS. London would continue to send its annual subvention to Belfast to keep the place running. Patriotic Ulstermen and women could still join Her Majesty’s armed forces. The Queen would carry on, happy and glorious, as head of state.​

“In the years to come, with the demographic alarm clock ticking away, it would be up to the rising generations in both communities to decide the long-term future. But that was always going to be the case.

“There would be an open border, exactly as there is today. Milk from the North could be processed in the South. Lorries wouldn’t be stopped or checked as they crossed from one jurisdiction into the other. There would be no tariffs. Goods and services would move freely … businesses in Northern Ireland, including the key farm sector, would enjoy the best of three worlds, British, Irish and European. Being EU-registered, companies would have automatic access to Continental markets … they would benefit, unlike England, from the ever-expanding range of EU trade deals with the wider world. If anything, the northern economy would flourish, enjoying advantages unobtainable elsewhere in the UK.

“Talk about cake and eat it!”

Now I could be wrong. It could be that a Brexit settlement along the lines said to be in prospect could result in Northern Ireland ending up negotiating its own Nixit from the UK and joining the Irish Republic. It could be that the mooted settlement would come to be seen as a stitch-up between the prime minister, the Taoiseach and Michel Barnier, with the DUP and the Unionists of Northern Ireland as the victims.

But what if it isn’t? What if the deal reflects no more than it says on the tin? And what if it enables Brexit?