A view of the Irish borderLorraine O'Sullivan / Reuters

Tired and frustrated, trust in each other all but gone, Britain and the European Union are on the brink of throwing away three years of painstaking work setting out the terms of their separation over a fundamental—and important—point of principle that both sides refuse to abandon: sovereignty.

The United Kingdom and the EU now have barely a week to agree on a compromise that would determine the rules of Britain’s departure from the bloc before a complex and unpredictable series of events is set in motion, almost certainly ending with a British general election. Should a divorce deal not be reached, Prime Minister Boris Johnson would likely have to ask the EU for a further delay to Brexit, meaning the election would almost certainly take place before the split has happened. Such a vote would pit Johnson’s pro-Brexit Conservatives against a coalition of anti-Brexit parties pushing for a second referendum with the ultimate aim of overturning Brexit.

To parties on both sides of the divide, an election offers the cure to Britain’s ills—a chance to break what has been a deadlock over how to proceed. For Europe, it holds the prospect of clarity over Britain’s intentions, with little obvious downside compared with where things stand today. One way or another, the U.K. should emerge with a clear plan for how it wishes to proceed.

Yet there is a greater risk than stasis: that any election held before Brexit occurs will unleash forces that may prove uncontrollable and irreversible, making reconciliation—between Britain and Europe, between Britain and Ireland, even between Britain’s domestic parties—harder, not easier.

An election before Brexit would see Britain’s warring tribes go into battle seeking mandates for principles that are not only incompatible but in direct conflict, which would risk worsening regional, political, and sectarian resentments—thereby stretching Britain’s political unity to a breaking point. In Scotland, separatists will demand a mandate from the majority there who oppose Brexit to stop the split from being forced on them by the rest of the country. In Northern Ireland, Protestant unionists and Catholic nationalists will urge their supporters to rally to their existential causes, the union with Britain and Irish reunification respectively, which had been settled by a decades-old peace treaty. And in England and Wales, where the majority supported Brexit in the 2016 referendum, voters will be asked to put aside previous political loyalties to rally to new objectives. What will emerge is unknowable, but risks fundamentally reshaping Britain’s relationship not only with the rest of the world, but also with itself.

The Brexit crisis is deep because the dilemma at its heart is a simple question: As a sovereign state, can the U.K. leave the EU in its entirety to conduct its own trade policy, or must Northern Ireland, the one part of the country that shares a land border with the EU, remain tied to some degree to European law to permanently avoid border controls with the Republic of Ireland, which will remain an EU member state?

London says, as a fundamental point of principle, that the U.K. must have the right to leave the EU as one united country. If this is not accommodated, Johnson has threatened, the U.K. will leave without a deal altogether. The EU, however, has countered that, as an equally fundamental point of principle, a border must be erected between Northern Ireland and the Republic of Ireland if different laws apply in the two. To not do so, it says, would be a threat to its sovereignty. Yet both sides also do not want a border to go up, because it would threaten the delicate peace settlement in Northern Ireland. It may be 2019, but Europe is arguing about whose writ runs in whose territory—all very Westphalia 1648.

The stakes could barely be higher: peace in Ireland, supply chains across the continent, security and police cooperation, financial stability, economic growth, cross-border travel, citizens’ rights. Were relations between Britain and the EU to be poisoned, almost every European country would be affected, from France and Germany, which risk losing a major foreign-policy partner, to Spain and Cyprus, which share borders with British overseas territories. Denmark, the Netherlands, and Belgium risk economic shocks; eastern-European countries major diplomatic headaches over the rights of their citizens in Britain. Outside of the Continent, the United States, Japan, China, and India, all of which have major investments in the U.K., face serious complications for their businesses.

No countries have more to lose, however, than Britain and Ireland. For Ireland, the risks are substantial: an immediate recession, the reimposition of border controls with Northern Ireland, and a complete breakdown of relations with the U.K., just to start with. For Britain, the threats are greater still: the immediate imposition of tariffs and restrictions on trade with Europe—its biggest trading partner, diplomatic ally, and security partner—as well as the prospect of instability in Northern Ireland, food-price increases, medicine shortages, mass delays at ports and airports, the disruption of travel for holidaymakers, the immediate loss of rights for British citizens in Europe, and the prospect of a reinvigorated secession movement in Scotland.

This is all potentially on the line in the election to come. Johnson, squeezed from the right by Nigel Farage’s Brexit Party, may be forced into pledges during the campaign that he will find difficult to unwind. If a deal cannot be reached with the EU before an election, Johnson’s Tories could go into the campaign seeking a mandate for no deal, rather than more time to find a compromise. The knock-on effects of no deal would be significant: For one, Britain would be in direct competition with the EU for investment, leaving open the possibility that the country would radically restructure its corporate-tax regime or take some other aggressive course of financial and economic action. The prospects for a future Britain-EU trade deal with the U.K. outside the bloc would, in this scenario, be dim.

For the opposition parties—Labour, the Liberal Democrats, and the Scottish National Party—there is also much at stake. Victory would mean a second referendum. But there are no guarantees what the question on the ballot would be, let alone which side would win, or what the implications of a “win” would be. There are no risk-free scenarios.

And for what? At the heart of the row lies a series of interconnected absurdities that could be lifted from the pages of a Joseph Heller novel. Dublin is willing to reimpose border controls with Northern Ireland now—at present, people and goods cross between Northern Ireland and the Republic of Ireland without encumbrance —rather than accept an imperfect British proposal that would require far less onerous checks than the ones that would be required if Britain leaves without a deal. European capitals, meanwhile, are willing to let this happen, jeopardizing trade with the U.K. worth £600 billion ($740 billion) a year, to protect a border with Northern Ireland where trade flows amount to £5 billion a year. And the U.K. is willing to tear up the biggest trade deal it currently has—and is likely to ever have—in the form of EU membership to negotiate new ones worth less that will almost certainly never apply in full to the one part of the country (Northern Ireland) that the crisis is all about.

European leaders are due to meet in Brussels on October 17—the last chance for a breakthrough before Britain’s scheduled departure on October 31. Last week, Johnson made a last-ditch compromise offer in an attempt to break the deadlock, proposing that Northern Ireland remain aligned with the EU in key regulations affecting cross-border trade. But in return, the EU had to accept that Northern Ireland would not stay forever in the EU’s customs union and would, at some point down the line, leave the zone with the rest of the United Kingdom. European leaders have so far said no.

Many in the EU are prepared to sit tight and wait until the U.K. concedes. Some have calculated that there is little downside to Britain having an election. One argument they’ve employed is that if Johnson wins and takes the U.K. out of the EU without a deal, he will quickly be forced to return to the negotiating table. If Johnson loses, Brexit could be called off entirely, saving Ireland the difficult choice of whether to raise a border with Northern Ireland.

Within 10 Downing Street, Johnson’s aides believe that this is a catastrophic mistake by Europe. Once an election has been called, especially in the event of a further delay to Brexit, the reaction of the country may well be to double down, becoming more euroskeptic and hostile to the Continent and Ireland; closing down the space for compromise, not opening it up; and creating new existential battles for the future of the U.K. internally.

In the game of Brexit, all the players are gambling that they can get their way. They can’t all be right. They may all be wrong.

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