In the summer of 1986 I walked along the border between Northern Ireland and the Republic of Ireland. Even the names of these two parts of the island were in dispute. Northern Ireland could, depending on the company, be called simply “the North”; it could also be “the Six Counties.” The BBC often called it “the province.” The Republic could be “the South,” or “the Twenty-Six Counties,” or “the Free State,” or even “the State.” In its constitution it was known simply as “Ireland.”

There are two international soccer teams on the island. One is called Republic of Ireland, the other Northern Ireland. But there is only one rugby team, made up of players from North and South and called Ireland. It is the same with cricket.

In this island, or this Ireland, in 1986, there were a good number of armies. In the North there was the British Army; in the South there was the Irish Army. In the North there was the police force, the Royal Ulster Constabulary, and also the Ulster Defence Regiment, a mostly part-time division of the British Army made up of local volunteers. This was not to be confused with the Ulster Volunteer Force or the Ulster Defence Association, both terrorist organizations that vehemently favored the link with Britain. In the South there was An Garda Síochána, also known as the Guards, the mostly unarmed police force. And there were a number of terrorist organizations that sought to encourage the British to leave, thus creating a united Ireland. These included the Irish Republican Army (IRA) and the Irish National Liberation Army (INLA). Since there was a customs border between the two parts of Ireland, there were also customs officers.

I walked alone, with the plausible alibi that I was writing a book.^* Since the border is not straight but snakes along old county lines, some of the journey was bizarre. One stretch of narrow country road leading north out of the town of Clones in the Republic, for example, goes through Northern Ireland for some yards before reverting to the Republic. There were no army patrols, no police presence, no customs post, no signs, and no explanation for this weird blip in the landscape. The exact place where South ends and North begins was carefully pointed out to me by a group of Southern men tidying the ditches for the local council.

And then there was the small matter of Felix Murray and his brothers. They lived in a cottage on the border between County Fermanagh in the North and County Cavan in the South. Their cottage, in fact, was cut in half by the border, although there was no visible line. All three brothers slept in the North, or so I was informed, although there had been a time when one of them slept in the South. (“Only an odd time now,” Felix said, “we sleep in the State.”) The border ran right through a sofa in their kitchen. Their electricity came from the South, their water from the North. They paid their dog license in the South, where it was cheaper, but they paid their television license in the North for the same reason. Two postmen came every day; the one from the South generally came earlier. They voted in the North.

Two rather more somber encounters on that walk remain firmly in my mind. These were with two men who lived in the North: Pastor Bob Bain and Alan Black.

When I first made telephone contact with Pastor Bain, he had two questions. The first one was: Are you a member of the INLA? I said I was not. The second was: What religion are you? When I replied that I was Catholic, he said, “You know you have to be born again.”

On November 20, 1983, Pastor Bain’s church was attacked by members of the INLA as Sunday evening service was being conducted. Three members of the congregation were killed and others injured. The church building was made of thin wood, so they shot through it, and they began to shoot low when the congregation threw themselves to the ground. The border was three miles to the south. Pastor Bain spoke of the South, the Republic, as an alien country. He believed that the terrorists had escaped there.

Toward the end of that summer of 1986, I came to the village of Bessbrook in County Armagh, about ten miles north of the border, which had no pub and no betting shop. I knocked on the door of Alan Black. What had happened to him was later described by Seamus Heaney in his Nobel Prize lecture:

One of the most harrowing moments in the whole history of the harrowing of the heart in Northern Ireland came when a minibus full of workers being driven home one January evening in 1976 was held up by armed and masked men and the occupants of the van ordered at gunpoint to line up at the side of the road. Then one of the masked executioners said to them, “Any Catholics among you, step out here.”

There was one Catholic, and when he finally identified himself, he was ordered to run. The gunmen, members of the IRA, shot the others—eleven Protestant men—killing ten. The survivor was Alan Black.

He was polite, welcoming, quiet-spoken as he invited me into his house. He believed it was important that I understood that two of the men had tried to shield Richard Hughes, the single Catholic, as they believed that he was the one to be shot.

The IRA members, it is presumed, fled south after the atrocity. No one has ever been charged with the killings of the men from Bessbrook. Some of those who committed these crimes may be still alive. Alan Black is still alive and still lives in Bessbrook.

The first change after that summer of 1986 came in November 1990, when Peter Brooke, the secretary of state for Northern Ireland, announced that “the British governmenthas no selfish strategic or economic interest in Northern Ireland.” Although this had been apparent for some time, it was clear, in its timing and its tone, that his speech was a kind of signal. It made it difficult to argue, for example, that the IRA campaign was designed to get the British out of Ireland. The British were ready to go anytime. What was needed was the consent of the people of Northern Ireland. Then came the implementation of the Maastricht Treaty in January 1993, which abolished the customs checks on the Irish border and allowed for free movement of goods, as it did on other borders between European countries.

On December 15, 1993, the Downing Street Declaration, negotiated between the British and Irish governments, stated:

The British Government agree that it is for the people of the island of Ireland alone, by agreement between the two parts respectively, to exercise their right of self-determination on the basis of consent, freely and concurrently given, North and South, to bring about a united Ireland, if that is their wish.

This might have been a comfort to both sides in the Northern Irish conflict. Catholics could welcome the idea that Britain would not stand in the way of a united Ireland. Protestants could see that, were it to come to a referendum, they would have, as they always had, a majority in Northern Ireland, so they would effectively have a veto. What the Catholics thus had was a statement that emphasized that the British were no longer a relentless, determined occupying force in Northern Ireland. The problem would be how to convince the Protestant population of Northern Ireland that a united Ireland would be in their interest.

The IRA decided to call a cease-fire, and slow, fitful negotiations began that culminated in the Good Friday Agreement of 1998. By this time, most of the heavily fortified border checkpoints had been dismantled. The agreement had to be ratified by plebiscite on both sides of the border. In the North, it was proposed that people would have the right “to identify themselves and be accepted as Irish or British, or both,” and that an administrative branch, the Northern Ireland Executive, would be set up in Belfast in which Protestants and Catholics would share power. Seventy-one percent of Northerners voted in favor of this agreement—almost all Catholics voted yes, but just over 50 percent of Protestants did.

In the South it was proposed to revise the wording of article 2 of the 1937 constitution, which had read, “The national territory consists of the whole island of Ireland, its islands and the territorial seas,” and to substitute a new, more inclusive wording for article 3:

It is the firm will of the Irish nation, in harmony and friendship, to unite all the people who share the territory of the island of Ireland, in all the diversity of their identities and traditions, recognising that united Ireland shall be brought about only by peaceful means with the consent of a majority of the people, democratically expressed, in both jurisdictions in the island.

In the referendum held in the South on the same day as the one in the North, this was supported by more than 94 percent of the population.

The next milestone was the Brexit referendum in June 2016. In England, 53.4 percent voted in favor of leaving the EU, while in Northern Ireland 55.8 percent voted to remain. (Polls suggested that 85 percent of Catholics voted to remain, but only 40 percent of Protestants.) Since the overall UK vote was 51.9 percent in favor of leaving, Northern Ireland had to follow the UK.

The problem was what to do about the Irish border, since after Brexit it represented a clear line not just between Ireland North and South but between the EU and the UK. If the border remained open, then goods could move freely and without regulation into the EU from the UK. If the border was to be policed, then the division of Ireland would once more be symbolized in the landscape by imposing official border crossings with long lines of trucks on both sides and by a return to a regime of easy smuggling. The liberating idea that citizens of Northern Ireland could be “Irish or British, or both,” would be much undermined by a hard border coming back as though to haunt us.

In the end, a protocol—a legal text annexed to the UK’s withdrawal treaty with the EU—was negotiated between the British and Irish governments and the EU. As Brendan O’Leary writes in Making Sense of a United Ireland: Should It Happen? How Might It Happen? (2022), “While legally Northern Ireland would be part of the UK’s customs union, for practical purposes it would remain within the European customs union for goods and agriculture.” If goods needed to be checked, this would not happen at a land border in Ireland but rather on a line in the Irish Sea. O’Leary observes, “Great Britain is fully out of the European Union’s authority, but Northern Ireland is not.”

Exporters in Northern Ireland, as a result of Brexit, have customs-free access to both the UK and EU markets, a luxury offered to no other country or region. It is, for customs purposes, two places, thus making it exceptional and anomalous.

But as a result of the Good Friday Agreement, the very existence of Northern Ireland is also open to question. There is a provision in the agreement for holding a referendum on a united Ireland in the North if “it appears likely” to the secretary of state, who is British, “that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland.” How this likelihood might be defined is not clear, but it is presumed that the secretary of state would be influenced by opinion polls. It is also stipulated that a referendum on unity would also be held in the Republic of Ireland at roughly the same time.

A yes vote would lead definitively to unity. “Once Britain leaves,” Sam McBride points out in For and Against a United Ireland, written with Fintan O’Toole, “it is not coming back.” A yes vote, according to an agreement in 2017, would mean that Northern Ireland, as part of Ireland, automatically rejoins the EU. A no vote, on the other hand, would not be definitive, since another referendum could be held seven years later.

While until recently Unionists (who favor the connection with Britain) formed a majority in Northern Ireland, this has now begun to change, not only because Catholics are having more children but also because more Protestants than Catholics are leaving. For example, “about 30% of Northern Ireland students go to Britain to study,” O’Toole writes. “And, in turn, only 30% of those who leave to study subsequently return to live and work in Northern Ireland.” If you define Catholics as those who either are practicing or were raised Catholic, then 45.7 percent of the population of Northern Ireland are Catholics,

compared with 43.5% who are “Protestant, Other Christian or Christian-related.” Almost one in five people in Northern Ireland either has no religion or declines to state a religious affiliation.

If it is clear, then, that a united Ireland is now a possibility, it is not clear how the unification process would actually be carried out. What institutions would be amalgamated or, indeed, abolished? Who would benefit? Who would lose out? It is also unclear if such a process could be carried out peacefully.

O’Toole and McBride come from different traditions in Ireland. O’Toole writes for TheIrish Times in Dublin and McBride for the Belfast Telegraph. It might be easy to imagine that if there were to be a debate about the future of the border, O’Toole would favor a united Ireland and McBride would not. But the book they have jointly written does not take refuge in easy categories or simple arguments. They each write two chapters in which they argue for and then against a united Ireland. It is a sign of their skill that the arguments they make for unity seem oddly solid and unassailable, and then their arguments against a united Ireland do as well.

But it is also proof that this debate is complex, as any referendum campaign will be. O’Toole and McBride were raised in different parts of Ireland. They should, in theory, be arguing with each other. Instead, each of them, with considerable subtlety and some eloquence, is arguing with himself, or at least suggesting that any opinion on this matter requires nuanced consideration.

The book is data-led, the arguments rational, the tone exemplary in its calmness. There is almost nothing about Ireland as a spiritual entity or an ancient territory that cries out for unity or a mystical country whose frontier has somehow been fixed by nature. O’Toole and McBride recognize that the very possibility of a referendum “affects the way people think about a wide range of political, social and cultural issues in the here and now.” They recognize that if unity were to come through referendum, then “loser’s consent,” which they define as “the willingness of those disappointed by the outcome to live with it because they accept that it is the freely expressed desire of the majority,” will be “vital to the future peace and prosperity of everyone on the island.”

Clearly it would not be helpful if Irish unity were seen simply as a Southern takeover of the North. O’Toole notes that the preference in the South is for a united Ireland to have a single set of institutions and services, such as a single police force, and wonders how such a force, run from Dublin, would gain allegiance from Protestants in Belfast unwilling to offer loser’s consent to a united Ireland. “Most people in the South,” he writes, “see a united Ireland as merely an extension of the state they live in.” Almost half of the Southern electorate would “be less likely to vote for a united Ireland if it required the creation of a new national flag and national anthem.”

In any referendum in the South, however, one of the looming questions would not be soft symbols but hard cash. Who would pay for Northern Ireland? In 2021 the North received an annual subvention of £13.9 billion from London, more than a quarter of its gross domestic product. McBride points out that “about one in three Northern Irish workers are in the public sector.” Who would pay their pensions in a united Ireland? O’Toole writes:

In the North, many more benefits are means-tested [than in the South], and many more families depend on them: half of households in Northern Ireland are eligible for a means-tested benefit compared with just a quarter in the Republic.

And since unemployment benefits in the South are more than twice those in the North, what would happen in a united Ireland?

The difference in living standards has affected life expectancy: male life expectancy in the South is now 81.3 years while in the North it is 78.8 years; female life expectancy is 84.5 years in the South and 82.5 years in the North. The difference in productivity per worker is even starker: it is, per O’Toole, “approximately 40% higher in the Republic than in Northern Ireland.” The difference between the wealth of the two parts of the country is also notable. McBride writes, “The Republic’s GDP is ten times that of Northern Ireland, even though its population is just over two and a half times bigger.”

This represents an astonishing change over the past century. In Belfast, in the heroic years when the Titanic was being built, 70 percent of female workers and 36 percent of male workers were employed in manufacturing. In Dublin the figures were 32 percent and 20 percent. “Overall,” O’Toole writes, “the share of manufacturing in total employment in Northern Ireland dropped from 35% in 1970 to 16% in 2000 and 11% in 2022. The North is no longer an industrial society.”

When the South joined the European Communities in 1973, a quarter of the workforce was employed in agriculture. That has gone down to 4 percent. The South has undergone many other changes, not least the collapse of the Catholic Church as a political force but also the emergence of a multicultural society: “There are more people of foreign birth in the Republic,” O’Toole writes, “than there are Catholics in Northern Ireland.” In the North, McBride points out, the discrimination against Catholics and the suspicion of Irishness itself have largely dissolved:

It is possible to live in Northern Ireland and be thoroughly Irish—to have an Irish passport, to have the state pay to educate one’s children in the Irish language, to play Gaelic sports as a member of the PSNI [the Northern Ireland police force], and to move seamlessly back and forth across the almost invisible Irish border.

The two parts of Ireland have health services that neither can be proud of, even if many in the North wish to hold on to the system they have—the British NHS. The Southern health system, O’Toole writes,

is a strange and unwieldly hybrid of public and private provision. In principle, everyone is entitled to free treatment…. Yet, as of January 2024, 2.4 million people—45% of the entire population—had private health insurance…. As a consequence, the Republic has a two-tier healthcare system in which one half of the population can buy reasonably quick access to treatment while the other half has to endure long waiting lists.

It seems pretty clear, then, that in a united Ireland, a health care system based on the NHS, in which service is free for everyone’s benefit, would be preferred. But McBride’s account of the NHS as it exists in Northern Ireland now does not support this: “The understandable love for what the NHS represents embodies devotion to a glorious ideal, but one that is years out of touch with reality.” The waiting lists for health care in Northern Ireland, for example, are much longer than in England:

Almost 38% of people on NHS waiting lists in Northern Ireland have been waiting for more than two years, compared with 0.016% in England…. Almost 62% of Northern Irish people diagnosed with a less survivable cancer will be dead within a year—the worst survival rates in the UK.

Improvements in the education system have been crucial to the modernization of Southern Irish society. This has not happened in the North, where education remains sectarian, with Protestants and Catholics attending separate schools. “Just 5% of schools are integrated,” O’Toole writes, “and just 8% of all pupils” attend them. In 2015, 35 percent of young adults (between twenty-four and thirty) in Northern Ireland had not progressed beyond lower secondary school, compared with 11 percent in the Republic. “The rate of early school leaving in the North,” O’Toole writes, “is approximately twice that in the South.” Only 23 percent of adults in the North have a college education; the figure for the Republic is 47 percent, perhaps because, as McBride writes, the Republic “has substantially lower university fees and a culture that appreciates the central value of education—both as a civilising force and as a key to economic progress.”

One of the most persuasive arguments in O’Toole’s chapter in favor of a united Ireland centers on education, especially on the education of those who have been left furthest behind under the Northern Irish system—working-class Protestant boys:

This has long been recognised not just as a social and economic problem, but as a political issue for the peace process…. Yet there is little evidence that Northern Ireland’s own institutions are capable of dealing with this “persistent” failure. The Republic, on the other hand, can point to the very considerable evidence that it has been much more successful in creating educational opportunity for children from poorer backgrounds.

The question then is: How does the Republic of Ireland feel about the North? It might appear from the overwhelming support for the Good Friday Agreement that a large majority would endorse the creation of a united Ireland. O’Toole, however, is cautious:

We know from the survey evidence that support for a united Ireland in the Republic is both very broad and very shallow. On one hand, polling…consistently shows that around two-thirds of respondents say they would vote for it in a referendum. On the other, when “terms and conditions” apply, these same prospective voters tend to take fright.

He also points out that many Southerners do not know the North: “Half of Southerners had taken no day trips across the border at all [in the five years before 2022] and two-thirds said they had no friends in the North.”

If one were asked to design a social media campaign—quick sound bites and flashing images—for a united Ireland, it would be easy to appeal to patriotism, mystical feeling, and hands across the border, not to speak of the joy of watching the Brits depart from our brave little island at long last, but a campaign against might even more effectively suggest that unity would involve an increase in taxation in the South that might last for two generations; it would mean the difference between an annual holiday in Spain or staying at home with your family in the rain. Also, does anyone want two warring factions that can’t even send their children to the same schools, that vote according to their religious identity, and that have made a basket case of their economy?

Because Ireland, unlike the UK, has a written constitution, it has a long history of holding referenda. For example, there was one in 1986 on a proposition to remove the clause in the constitution that banned divorce. This was defeated. The referendum was repeated in 1995, and the proposition passed. In 2001 a referendum on the Treaty of Nice, which proposed a reformation of the EU’s institutions, was defeated, with 53.9 percent voting against. When the referendum was repeated the following year, 62.9 percent voted in favor. So, too, the Treaty of Lisbon was rejected in 2008 and passed in 2009.

In these cases, the electorate changed its mind when more information became available and when thorny questions had been clarified. In 2021 a deliberative forum was organized in the South, O’Toole writes,

to tease out the views of a representative sample of Southerners about how Irish unity might happen and what it might look like…. An overwhelming majority of participants…said they “favoured telling voters before the referendum the specific model of a united Ireland that was on offer.”

He points out that this presents a difficulty, since voters in the North seem to favor “a devolved model,” with a parliament in Belfast and many institutions that are locally run, “while the Southern public favours integration. In particular, Protestants in Northern Ireland are ‘extremely opposed to the integrated model.’” What this suggests is that a debate on whether there should be a united Ireland at all will have to be followed closely, or perhaps preceded, by a discussion about what kind of polity should emerge.

O’Toole quotes an opinion poll from 2022 in which 66 percent of respondents in the Republic said that their single biggest concern was “whether a united Ireland would be peaceful.” The same pollsters a year later found that 52 percent of people from a Protestant/Unionist background in Northern Ireland “could live with” a majority vote in favor of a united Ireland, but 23 percent said that they would find it “almost impossible to accept.” He writes:

It would be wrong to assume that most of those people would resort to violent resistance, but we know only too well from Irish history that relatively small numbers of people, if sufficiently well organised and motivated, can create mayhem and cause immense harm.

McBride writes about the threat of a return to violence, especially violence from Unionist groups that would not be inclined to offer loser’s consent to a united Ireland, “yet a rational analysis of the strengths and weaknesses of those who might murder to get their way demonstrates that they have considerable vulnerabilities.” He concludes: “Of all the potential problems, this one should not be dismissed. But there are reasons to believe that a loyalist insurrection, were it to happen, would be unsuccessful.”

This is McBride arguing for a united Ireland. But in his chapter arguing against, he writes the most personal statement in this book:

I can live with unity or Union. Even if the economic claims turn out to be wrong, I can live with being poorer. But I don’t want to live, and I don’t want my children to live, with civil war or anything approaching it.

A few pages earlier, he had set the problem out starkly:

Even if it can be argued that a united Ireland would be unquestionably better, if there is a significant possibility that the journey towards that destination would include bloodshed, it is a fundamentally different proposition. If it were possible to calculate now how many dead there might be, what figure would be acceptable? One? Twenty? A hundred?

O’Toole and McBride show us what two enlightened policy wonks can do for Ireland. They enact in their writing the idea that easy divisions and stark binaries make no sense in Ireland now, O’Toole insisting that “there is a whole world of complex, fluid and hyphenated identities,” McBride quoting the English anthropologist Anthony Buckley:

There are no distinctively Protestant or Catholic dialects, nor agricultural practices, nor housetypes, nor pottery techniques, nor styles of cooking. Family life is much the same on both sides, as indeed is the broader social morality.

Both writers, in their chapters in favor of unity, show that it is easier to be optimistic and eloquent about unity than about the status quo. McBride, in his case against unity, writes:

From its inception, Northern Ireland has been a place of inbuilt compromise. It’s imperfect to everyone, but right now it’s the best way of being able to share this piece of ground without the potential for unrest whose ultimate boundaries are unknowable.

O’Toole considers the levels of inertia and mismanagement in the Republic of Ireland: “It is simply fanciful to imagine that such a creaking system is capable of managing, in addition, all the immense practical problems that unification would bring.”

On the other hand, in his “yes” chapter O’Toole sees unity

not just as an idea or an aspiration, but as a process of tangible improvement in the daily lives of all who share the island. It can become not the fulfilment of an ancient historic destiny but the stimulus to create a more prosperous, sustainable and socially just future.

McBride in his “yes” essay sees the Protestant and Presbyterian traditions in Northern Ireland not as noisily withholding loser’s consent but rather as having the potential to enrich a new Republic of Ireland:

Unity would mean reclaiming the wider diversity of the island by reintegrating the dissenting Protestant tradition and the Presbyterian culture of logical debate…. It would be a reimagination of what Ireland is, and what it can be.