This is the script for my video posted on July 3, 2026. Watch it on TikTok.
Ireland has been split into separate parts since 1921, but after over 100 years of political strife and public violence aiming to bring Northern Ireland and the Republic of Ireland together again, the prospect could actually be on the table in a matter of years. But why are the two parts separate to begin with, and how would their reunification influence geopolitics?
To answer those questions, we have to start in the 17th century, when the British Crown first confiscated native Irish land and established a colony in the northern region of Ulster. Ireland had been Catholic for a thousand years, and attempts to force the Protestant Reformation onto it largely failed. But Britain settled thousands of English and Scottish Protestants there with the aim to control and anglicize the population, and they were largely successful, though in 1641 a rebellion took place to try to end anti-Catholic discrimination and undo Britain’s colony. Around 4,000 settlers were killed in the violence, with thousands more dying of cold and disease after being driven from their homes. Contemporary propaganda inflated the toll into the hundreds of thousands, and those inflated numbers were used to justify brutal reconquest. Britain recaptured the region and doubled down, moving in tens of thousands more protestants. In 1801, the Kingdom of Ireland became part of the United Kingdom.
But in 1918, after over a century of British rule, Ireland’s Catholic nationalist majority under the Sinn Fein party won most Irish constituencies for the British parliament, but instead of going to London, they convened a new Irish parliament and declared independence, provoking a war with Britain fought by the guerrilla forces of the Irish Republican Army, or IRA. Neither side could land a decisive blow, and the war ended in a truce and a negotiated treaty that gave most of Ireland dominion status, not the full republic the IRA fought for. During the war though, the British government introduced a bill that carved out six of Ulster's nine counties as a new entity called Northern Ireland, with its own government, chosen precisely because those six counties had a reliable Protestant unionist majority. When the rest of the island split from Britain, Northern Ireland opted to stay.
This sparked a period of intense communal violence in Ulster, particularly in the Northern Irish capital of Belfast, with hundreds killed by the time things settled. Roughly 10000 Catholic workers were expelled from Belfast's shipyards and factories, and thousands of families fled south or were burned out of mixed neighborhoods, hardening the informal segregation that persists to this day. In the mid-20th century, a campaign began in Northern Ireland to end discrimination against Catholics and nationalists, but this was not received well and provoked the beginning of the Troubles, which you have probably heard about.
For 30 years, people in favor of a united Ireland fought against the British government in a sort of low-intensity irregular conflict, and though it was not a religious war, the sides were largely divided along protestant and Catholic lines. The Northern Irish police, the Royal Ulster Constabulary, were overwhelmingly protestant and known for brutalizing Catholics. Walls were put up to keep communities apart, and British troops were deployed in 1969, initially welcomed by many Catholics as protection, but events like Bloody Sunday in 1972, when soldiers shot dead 13 unarmed civil rights marchers, turned the army into a recruiting engine for the IRA. Republican paramilitaries like the Provisional IRA waged a campaign of bombings and assassinations against security forces and civilian targets, aiming to force Britain out. On the other side, loyalist paramilitaries like the UVF and UDA killed Catholic civilians, often at random, to terrorize the nationalist community. More than 3,500 people died in the end. Republicans were responsible for about 60 percent of the deaths, loyalists about 30 percent, and state forces about 10 percent, and over half of all the dead were civilians. And by the late 1980s it became clear that the IRA couldn’t bomb Northern Ireland out of the UK and the British state could not defeat the guerrilla forces. So they sought a political solution.
In 1993, the British and Irish governments issued the Downing Street Declaration to enshrine the principle of consent guaranteeing that Northern Ireland would remain part of the UK unless the majority of its citizens voted otherwise. After substantial progress on border agreements, the Provision IRA and other paramilitary groups announced ceasefires, which opened the door to formal negotiations. And in 1998, the UK and the Republic of Ireland signed the Good Friday Agreement that radically reformed nearly every aspect of Northern Ireland’s dynamics, reforming policing, disarming paramilitaries, and creating a power-sharing government, among other things.
The Good Friday Agreement has held ever since, and under Schedule 1 of the Northern Ireland Act issued the same year, the UK Secretary of State for Northern Ireland not only has the power to call a border poll at any time—they have a mandatory duty to call one if it ever appears likely that a majority of voters would wish to join the Republic of Ireland. Once a poll is held, another cannot be called for at least seven years, and under the Good Friday Agreement framework, the south would hold its own referendum at the same time, because unification requires consent from both jurisdictions. In 2025, the British and Irish governments both stated that there are no indications the necessary conditions are met, and the Irish Taoiseach stated there should be no border poll before 2030, though the Sinn Fein party has repeatedly called for referendums this decade.
There are several factors that could actually lead to this happening. The 2021 Northern Ireland census, for example, showed that Catholics and those with a Catholic background outnumber protestants for the first time since Ireland’s partition. British only national identity fell from 40% in 2011 to 32%, and Irish only identity climbed from 25% to 29%. In 2022, Sinn Féin became the largest party in the Northern Irish Assembly for the first time ever, and in early 2024, when the Assembly returned from a two-year unionist boycott, Michelle O'Neill took office as the first nationalist First Minister in Northern Ireland's history. Polling still shows more Northern Irish voters would choose to stay in the UK than to leave, with unification support typically landing somewhere in the 30s to mid 40s depending on the pollster. But the gap has been narrowing, and among voters under 45 some surveys show unification ahead
Then there’s the fact that 56% of Northern Ireland voted to remain in the EU in 2016, but the UK left anyway. The Republic of Ireland, meanwhile, is a part of the EU’s single market, and though a bespoke protocol kept Northern Ireland inside the EU's single market for goods while remaining in the UK market, a dual access arrangement no other place in the world has, EU membership and the expanded opportunity it provides to people is definitely a factor in the decision to stay or leave. The Republic has seen an economic transformation recently, with corporate tax receipts hitting a record 39b EUR in 2024 and a sovereign wealth fund actively growing, while Northern Ireland’s economy has been underperforming and is supported by a roughly 10b pounds per year to keep it up and running. But Northern Irish residents get free healthcare, while the Republic is regularly described as the only Western European country without universal primary care coverage.
The impact of a reunification would be disproportionately large. The UK would face a symbolic blow to its national cohesion that in theory could feed the Scottish independence movement that’s been brewing. Unification would also pull Northern Ireland out of NATO, since it is currently alliance territory as part of the UK, and neutral Ireland has never joined, and unlike Britain, Ireland spends around a quarter of one percent of its GDP on defense, the lowest in the EU. Even that understates how small the military is: there are fewer than 8,000 troops, with no fighter aircraft and minimal ability to monitor its own waters, even though roughly three quarters of the transatlantic cables in the northern hemisphere pass through or near Irish waters. Russian naval activity is increasingly observed in their vicinity.
Realistically, a unification is unlikely at least for a few years. The trigger hasn’t been met for referendums, and though the Catholic and non-religious nationalist population is growing in Northern Ireland as young people come of age and older protestants decline, the demographic and political shifts required for a major change are still a long way off.
Keep reading
- Why hasn’t Scotland gained independence from the UK?
- Why is Corsica fighting for autonomy from France?
- Why does Wales still speak Welsh when Ireland stopped speaking Irish?
I’m writing a book called Groundwork about the buried history beneath geopolitics. Join the waitlist to hear when it has a publisher, a cover, and a release date.