Brexit is probably the United Kingdom’s death knell

A hundred years ago, Northern Ireland was established, and with it the current shape of the United Kingdom. That familiar form has survived World War II, the Troubles, and no fewer than three referendums on Scotland's political status. But it may not survive Brexit, which has scrambled political allegiances and rekindled separatism in Scotland and Northern Ireland. Today, Brexit has placed unprecedented stress on the already fraying bonds between the United Kingdom's four constituent countries, putting the union's future in doubt.

The gravest and most immediate threat comes from Scotland, which headed off an independence referendum in 2014 but could hold a second one soon, thanks to the strength of the Scottish National Party (SNP). The party currently holds 47 of Scotland's 59 seats in Westminster and a further 61 (four short of a majority) in Holyrood. Buoyed by the fallout from Brexit, the SNP is projected to win an outright majority in this year's Scottish Parliament election, claiming a mandate for a second independence referendum in the process. The strong likelihood of a SNP majority in Scotland's devolved Parliament should worry unionists; the last time it happened in 2011, an independence referendum followed just three years after.

Of course, any second independence referendum would have to run through Westminster, where Prime Minister Boris Johnson has promised to "return to sender" any request to hold one. But that could soon change. Britain's next general election is scheduled for 2024, and in the likelihood that neither Labour nor the Tories win a majority, the SNP will play kingmaker. Their price will be a second independence referendum. Labour leader Keir Starmer has ruled out any Labour-SNP coalition, but his calculus could change once faced with the prospect of a fifth consecutive Conservative government. The Tories' Johnson has likewise ruled out any Conservative-SNP coalition, mindful that it could lead to Scotland's departure. But the famously opportunistic Johnson has disappointed unionists before, and it's not out of the question that he could again for political survival. What's clear is that, whether after a landslide in this year's elections for Scottish Parliament or after coalition talks at Westminster, the SNP is in due course to get its second referendum.

And this time, there is every reason to believe they will win it. Polls have shown consistent majorities in favor of independence. The SNP has seen its approval ratings skyrocket over its handling of COVID-19. And the most effective argument deployed against independence in 2014—that secession would jeopardize Scotland's place in the EU—is now void. Moreover, the last referendum revealed deep age disparities that should worry unionists; 67.1 percent of those over 70 voted to stay in the union, while 62.2 percent of those aged 25-29 voted to leave it. In other words, Scotland's older, pro-remain generation is being replaced by one that's both more open to independence and keener on securing Scotland's place back in the EU.

The specter of separatism is just as pronounced across the Irish Sea. When the enclave of Northern Ireland was formed 100 years ago, Protestants –overwhelmingly Unionist— outnumbered Catholics by two to one. But their majority has since disappeared. The 2011 census saw Protestants fall below 50 percent of the population for the first time, and the 2021 census is projected to see Catholics outnumber Protestants outright. These changing demographics became apparent in 2019's UK. general election, when nationalist parties (who seek to rejoin the Republic of Ireland) won more seats than unionist ones for the first time ever. Polling, too, has shown growing support for reunification, including a landmark 2019 poll that showed a majority in favor of leaving the UK.

It is Brexit, however, that has most reignited the question of Northern Ireland's political status by bringing it into closer union with the Republic. In many ways, Brexit has brought Northern Ireland closer to Dublin than London; goods that travel from Northern Ireland to the Republic face no customs barrier, whereas since Brexit those that travel from Northern Ireland to the rest of Britain now do. Irish unification has also become a more salient issue in the Republic, where the nationalist Sinn Fein (the former political outfit of the IRA) finished narrowly ahead in the 2020 general election. The potent combination of changing demographics, Brexit, and Sinn Fein's newfound prominence south of the border means the question of Irish unification will loom large in the coming decade.

Taken together, the dual threats of Northern Ireland and Scotland pose an unprecedented risk to the UK.'s current shape. And if both were to leave it, it's not unimaginable that Wales could follow them out the door—though it is unlikely. The ties between England and Wales are much stronger, dating back to the Edwardian conquest of Wales in the 13th century and reinforced over eight centuries of closer economic and geographic proximity. And whereas Northern Ireland has the chance of reunification with a buoyant Irish economy, and Scotland hopes to keep reaping the benefits of North Sea Oil, Wales' economic prospects on its own are not as promising.

But even in Wales, nationalism has a foothold; a recent poll pegged support for independence at 23 percent, and the separatist Welsh party Plaid Cymru (which already holds four seats in Westminster) showed some latent political strength with their second-place finish in 2019's European elections. Their prospects could increase with the revival of the Welsh language, which has bolstered a Welsh national identity distinct from that of Britain. Moreover, separatist movements tend to reinforce each other, and Welsh nationalists would no doubt feel emboldened if their counterparts in Northern Ireland or Scotland were to leave the UK.

There are reasons to doubt the United Kingdom will fall apart. Any deal ultimately depends on the goodwill of Westminster, and the willingness to risk letting anything go. In Northern Ireland, for example, Irish Catholics may vote for the status quo to preserve their access to Britain's vaunted National Health Service as opposed to the more privatized Irish model. And the UK.'s current shape has survived much worse. But as separatist movements from Catalonia to Kosovo simmer across the continent, the UK. would be wise to take caution. Politically, Britain may no longer be part of Europe, but neither is it immune from the currents reshaping it.

A recent graduate of Georgetown's School of Foreign Service, Brent Peabody currently works as a national security analyst in Washington DC.