Britain is one of the oldest and most stable democratic societies in the world. For centuries, it conducted itself on the world stage with canny self-interest and the occasional moment of high principle. Sometimes it was a force for good, sometimes for bad, but it was always rational.

Over the past three years, however, ever since 52% of voters decided to leave the European Union, Britain has gone completely bonkers. Each day, the country has been forced to go through some new level of embarrassment, some new substrata of delusional thinking. We keep imagining that we have finally reached the lowest possible point, that things simply cannot get any more embarrassing than this, and then, no, it turns out they can always get worse.

Brexit is probably the most complex, technical, never-ending news story in global politics, but at the heart of it is a simple question: Do you believe in objective reality? Is there a shared set of facts which apply to the world, which we can all agree on?

Early on, the debate hinged on this issue. You either accepted objective reality, in which case you recognized that Brexit was going to be a painful process toward a suboptimal outcome. Or you didn’t, in which case you saw it as a heroic adventure of macho national destiny. It goes without saying that the first team lost.

At the heart of the Leave campaign was a large lie: Britain could leave the EU, take full control of every aspect of its regulations and laws, and still maintain frictionless trade with Europe, its largest market.

Later this summer, Boris Johnson — the former Mayor of London whose calculated buffoonery masks a complete absence of principle — will almost certainly become prime minister, after being elected to the post by Conservative MPs and party members. It’ll be another horrible milestone — the political equivalent of painting a giant clown mask on the face of the country. Britain will be giving up any claim to be a serious nation. How did we get here? How did an advanced democratic society dismantle itself so quickly?

The Brexit referendum took place three years ago yesterday. At the heart of the Leave campaign was a large and sustained lie, namely that life does not involve trade-offs. The Leavers insisted that there were no downsides to Brexit: Britain could leave the EU, take full control of every aspect of its regulations and laws, and still maintain frictionless trade with Europe, its largest market. In short, the religion of Brexit — and that’s what it is, an act of faith — demanded the end of any belief in objective reality.

To believe in objective reality, after all, is to acknowledge that the world is actually full of trade-offs. And since the EU is the most ambitious transnational project in the history of mankind, it demands heavy-duty trade-offs. It works basically by melting European economies together into one.

This happens in a couple of ways. The first is tariffs, which are taxes on goods crossing national borders. In the EU, tariffs are completely eradicated inside the bloc.

The second is regulation. This is the main obstacle to trade between countries. If you pass a law on the chemicals in children’s toys, for instance, or health requirements on meat, then you have to put someone on the border checking the products coming in to make sure they comply. The EU response is to harmonize regulations. The laws on products like children’s toys or meat are the same in all the 28 member states of the EU. Unquestionably, this implies a loss of national sovereignty. Once you’re an EU member you do not have full control over every law you pass. Instead, you are part of a continent-wide discussion in which you decide on those rules for everyone.

The advantages of the EU arrangement, however, are extensive. One is peace. The idea was to make it impossible for countries to go to war with one another by melding their economic interests together. Historically, Europeans have been big fans of killing one another, but after the EU was created, in the ashes of World War II, continental conflict has been increasingly a thing of the past.

Another advantage is frictionless markets for goods and services. The European single market is the most advanced trading system in history. Goods can be produced and sent anywhere on the continent, with no taxes or regulatory checks. Services are more liberalized than anywhere else on earth, with extraordinary freedom for workers to start a business, or join one, wherever they like. Freedom of movement means that anyone, from any European country, can holiday, live, work, love, or retire in any European country.

A third advantage has to do with scale. The EU allows lots of medium-sized countries, which would be otherwise economically overpowered by states like China or the U.S., to club together as one entity and go toe-to-toe with anyone.

Britain voted to say goodbye to all this. That meant it would get control over regulations on products, and, most important for many Leavers, it would be able to stop European immigrants coming to the U.K. Large influxes of eastern European workers and a relentless drumbeat in the right-wing press had convinced many Brits that immigration was at an unsustainable level. In actual fact, countless studies have shown that immigrants boosted the British economy and provided a young and eager workforce to care for the country’s elderly population. But the anti-immigrant rhetoric of the populist right won out during the referendum.

Leaving the EU meant that Britain would be poorer. There would be checks on the goods coming to and from Europe, which would devastate its trading network.

And leaving would have one other, even more severe, consequence: it would threaten peace in Ireland. The island of Ireland is split between the Republic, an independent country that is and will remain in the EU, and Northern Ireland, which is part of the U.K. and therefore subject to the decision to leave the EU. The border between them is open. You can travel across it without knowing it is there. That is not some curiosity. It is a key requirement of the peace process that brought an end to the Troubles in the late 90s.

The more Brexit is shown to be disastrous, the greater the need for a witch hunt against the ideologically impure.

If Britain left the EU without signing up to its rules, customs and regulatory checks would suddenly be needed on the Irish border, to ensure that goods moving into the EU met European requirements. And then peace would be at risk. A process based on North-South cooperation would suddenly come apart at the seams.

The Brexit camp never conceded any of this. They spoke about magic technological solutions that would allow customs and regulations to be checked without any infrastructure, even though no border anywhere in the world works like this. They dreamed up obscure little bits of international law that would solve their problems in some imaginary parallel reality.

They also accused their critics, of whatever stripe, of being in some kind of establishment conspiracy, or lacking in patriotism. In the years since the referendum they have accused almost everyone of trying to “thwart the will of the people:” journalists, members of parliament, the judiciary, the House of Lords, the Treasury, the prime minister, the EU, academics, policy experts, and even some of the people who actually led the campaign for Brexit. The more Brexit is shown to be disastrous, the greater the need for a witch hunt against the ideologically impure.

A shrill debate took hold. It wasn’t about the EU, really, or customs or any of that stuff. It was about identity. The Brexit fight was a culture war between people who wanted a form of national purity and those who wanted a more open, international country. It was Trump’s wall, on a system-wide scale.

Three years ago, a new British government was formed in the wake of the referendum result, headed by Theresa May. She was like an android which had only been half-completed and was, therefore, struggling to mimic human behavior. She fought hard to leave the EU, but eventually, reality intervened in the form of something called “the backstop.”

This was the mechanism, negotiated with the EU as part of the withdrawal agreement, that would allow the British to abide by their commitment to keep the border in Ireland open. It said that unless some other way was found to preserve the open border, Northern Ireland would be locked into the EU regulatory system until an alternate system could be found.

But if Northern Ireland was locked in, then all the U.K. would be. And that meant the illusionary dream of limitless British freedom was gone.

The Brexiters screamed betrayal, even though, in actual fact, the backstop was an insurance policy. It would force them to keep their promise to Ireland if their rhetoric about how harmless Brexit was turned out to be false. Predictably, they exploded with indignation.

One after another, the politicians in charge of Brexit walked away. It was easier to shout about betrayal from the sidelines than to try to deliver a version of it that would be accepted by the EU and the British parliament. May attempted to get the deal through the House of Commons three times, failed three times, and then resigned in tears.

For a few short months, British politics had come into contact with objective reality and the response was total chaos. The compromises required by Brexit were too much for its supporters to psychologically accept after years of delusion.

There was one obvious response to this crisis. It was to put the deal to the public. The first referendum showed support for the principle of leaving the EU. Now that there was a legal document outlining exactly what that entailed, and it seemed right that there should be a further vote on whether the reality of Brexit also had support. A second referendum would confirm the project’s democratic legitimacy and sidestep the stalemate in the House of Commons.

But the idea of letting people vote on the reality of Brexit, rather than the fantasy of it, is considered sacrilege by its supporters. They have fought tooth-and-nail to prevent it. Nevertheless, it remains as the only obvious way to break the deadlock, the logical solution the political class cannot countenance, but which refuses to go away. It may yet prevail, not because those campaigning for it are particularly effective, but because all the other options are so much worse.

Britain used to be a fundamentally calm country, which celebrated its resistance to utopianism. Three years of culture war have basically driven it insane.

Instead of grasping this alternative, the Conservative party retreated into fantasy again. In the weeks after May’s resignation, countless candidates emerged to replace her. Just one — a former infantry officer named Rory Stewart — was prepared to admit that Brexit required trade-offs. His colleagues eliminated him last week. They hated the noise he was making.

Boris Johnson is almost certainly going to win the contest for the prime ministership. They used to say that politicians campaign in poetry and govern in prose. Johnson’s approach is different. He is painting a great and glorious rainbow highway, for the unicorns of the Brexit debate to travel up into the sky. His message is a ceaseless barrage of impossible nonsense.

Britain used to be a moderate, good-natured, and fundamentally calm country, which celebrated its practical judgment and resistance to utopianism. Three years of culture war have basically driven it insane. It is now on the verge of making one of the most deceitful and self-interested politicians it has ever known prime minister, so that he can pursue an imaginary strategy for an unattainable outcome.

Johnson will face the same problem his predecessor did: objective reality. And when he does, the same thing will happen to him as happened to May. Then we will be here again, probably not so long from now, going around in the same old mortifying circles, until a grown-up comes along and says what is currently unsayable: Trade-offs exist, and you do not help your country by pretending otherwise. It’s a lesson Britain has well understood for hundreds of years. The sooner we remember, the better.