Toby Melville / Reuters

Britain and the European Union begin negotiations over a new trading relationship today, but like in Willy Wonka’s chocolate factory, a strange unreality hangs over everything.

The two sides have given themselves just 10 months to agree on a new trading relationship that will supersede the no-tariffs, no-checks system that currently exists. Last week, the U.K. and EU each published a “mandate,” setting out what they wanted from any new deal. Taken together, their opening positions left just about enough middle ground for a final agreement to be struck, analysts said, narrow though it may be.

The problem, though, is not that a compromise has become impossible or even unlikely—few believe either is yet the case. The problem is the apparent hands-over-the-eyes failure of either side to accept that the world has changed since Britain left the EU on January 31.

London appears to be denying the reality of the price it has already paid to extricate itself from the EU’s legal order: de facto border controls between Great Britain and Northern Ireland (both sovereign parts of the United Kingdom). Brussels, in return, appears to be denying the reality of Brexit altogether—that Britain has decided to leave the EU’s legal order, regardless of the economic costs. So far, Brussels’s position is as straightforward as it is unacceptable to London: The price of a new trading relationship is the U.K. abiding by some EU standards, set by the EU and enforced by the EU’s court in perpetuity.

As the two sides gear up for the fraught negotiations about to ensue, the unreality is this: The EU seems unable to grasp the nature of Brexit; the U.K. seems unable to grasp the price it has paid to get it. The consequences could be a far more profound rupture than either wants or is necessary—and, for London, a far more difficult relationship with Northern Ireland (let alone Scotland).

To understand why all this is happening, going back to basics is important. The EU works as a collection of sovereign states that agree to give up direct national control over areas of daily life, including food standards and fishing rights, and international trade, immigration, and social standards. They do this, pooling national control into a body that sits above them, because they believe the benefits are worth it, whether in terms of prosperity, peace, or regional influence. Many Europeans, including Brits, also believe in the project as an expression of identity; they are European and not just French or Dutch, Irish or Greek.

Brexit is a rejection of this bargain. In seeking to “take back control” of Britain’s money, laws, and borders, London is exercising its right to leave the higher jurisdiction of EU law that keeps the organization together, accepting that, as a result, it cannot enjoy the benefits of membership: ease of trade and travel and, fundamentally, influence over the laws made in Brussels.

What has complicated the whole endeavor is that the U.K. is not a normal nation-state, but itself a union of nations. One of those—Northern Ireland—cannot even agree on whether it is a nation or not, and sits not on the island of Britain, but on the island of Ireland, sharing a land border with the Republic of Ireland, a separate country and EU member state, to the south.

If it weren’t for Northern Ireland, as Angela Merkel is alleged to have told Boris Johnson, Brexit would be more straightforward. But Northern Ireland does exist, and will remain a sovereign part of the U.K.—the United Kingdom of Great Britain and Northern Ireland—until a majority of its population chooses otherwise. Yet almost half of its citizens consider themselves Irish, not British, and would resent any post-Brexit disruption to their lives crisscrossing the border with the Republic. To maintain the status quo, London, Dublin, and Brussels agreed to keep the border open as before.

Yet the only way to keep the border open was for EU law to apply north and south of it. In other words, EU law would have to continue to apply in a part of the U.K., even after the U.K. had left the EU. London was then faced with a choice: Should the whole of the country accept EU law, or should an internal border be erected? Theresa May chose the former and lost her job, Boris Johnson chose the latter and won a landslide general-election victory.

Fast-forward to today and Johnson’s problem is that having paid this significant price to maximize mainland Britain’s freedom from EU jurisdiction, he is refusing to accept that the harder he pursues this freedom, the firmer the divide will be with Northern Ireland. Matthew O’Toole, a former Downing Street official who is now a member of the Northern Ireland assembly, told me the choice for London was clear: “If the U.K. is serious about wanting to diverge entirely from EU rules, that means checks on goods as they cross the Irish Sea between Britain and Northern Ireland.”

Johnson’s other problem—more politically pressing than the first, given that Northern Ireland’s plight has not provoked much sympathy among British voters—is that having agreed to a price for the U.K.’s freedom, the EU, from London’s perspective, has now increased the cost, and said that any future trading relationship must be based on EU law. This is the EU as the famed Hotel California: You can check out, but you can never leave.

Sam Lowe, a senior research fellow at the the Centre for European Reform think tank, told me that, at its core, the EU did not accept that its negotiation with Britain was one between equals. He said the EU was “trying to use its economic weight to impose conditions on the U.K. it wouldn't normally ask of others.” Canada and Japan both have similar trade agreements to the one the U.K. is asking for, but Brussels has not required those countries to accept the supremacy of EU law. The economic reality for Britain, though, is that the EU is the regional hegemon, and this is how it behaves with countries on its periphery.

Raoul Ruparel, who advised May on Brexit, said the logic worked both ways. "There are elements of denial in the opening positions of both sides,” he told me. “The EU seems unable to accept that the U.K. will no longer be part of its legal and regulatory order [but] the U.K. doesn't yet seem to have fully accepted the trade-offs that will need to be made to secure a deal in such short order."

The truth that dare not speak its name is that while Brexit was—and is—about taking back control, Britain ceded total control of Northern Ireland to do so, and the EU lost control of Britain in the process.

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