Everyone is happy. Well, everyone except Nigel Farage with his shouts of “betrayal”. The EU says it is happy with the deal struck with Theresa May on Friday morning. Mrs May says she is happy. Truth to tell, the prime minister and her aides are gasping with stunned relief. Even more remarkably, Boris Johnson and Michael Gove, standard bearers of the hard Brexiters in the cabinet, claim to be happy. When he is in sycophancy mode rather than treachery mode, Mr Gove could give tutorials in how to be oleaginous to Uriah Heep. “The prime minister has won,” he oiled during his tour of the studios to sell the settlement to Tory Brexiters as “a significant achievement”.

Cabinet members who want a soft Brexit say they are, yes, happy. Nicky Morgan, speaking for pro-European Tory backbenchers, acclaims “great progress”. Business groups are happy. Even the Labour party says it is sort of happy. The Irish government is happy. Northern Ireland’s Unionists are not exactly happy – they don’t do smiley faces – but at least they are not as snarly as they were earlier, when their objections threatened to derail the deal.

A chorus of Tory commentators are now singing hallelujahs to the prime minister. They applaud Mrs May for the apparently remarkable feat of aligning her riven cabinet, her divided party, the island of Ireland and the EU behind the same deal. Can this be the same Mrs May whom the Tory choir had previously been bewailing as a maladroit incompetent who could be out of her job by Christmas? The very same.

This outbreak of delirium ought to make us extremely suspicious. Everyone cannot be happy. Someone is deluding themselves about what has been agreed – or they are trying to fool us.

The prime minister says that getting to an agreement involved “give and take on both sides”. She didn’t say that Britain has given and the EU has taken. The EU has made some concessions that are quite important, but most of the more significant compromises have come from the British side. This is not surprising – indeed, it was utterly predictable – because that has been the pattern of the Brexit talks since the very beginning. The government huffs that it will stand firm on this and puffs that it will not compromise on that. Then it gets mugged by reality. That reality is that the bulk of the conceding was always going to come from Britain because of the asymmetrical bargaining strengths of the two sides.

As Sir John Kerr, the British diplomat who constructed Article 50 has pointed out, the process was designed to disadvantage a withdrawing country. While the EU has quite a lot to lose from this hazard-strewn enterprise ending in a disaster, the risks to Britain’s economy have always been very much higher. When the talks – and Mrs May’s job – looked to be in jeopardy earlier in the week, companies weren’t saying that they would be pulling investment from Italy or Flanders or Slovakia if there wasn’t an agreement to progress the Brexit process to the next phase. Companies were saying they’d be making business decisions that would leave Britain the poorer.

This structural weakness in Britain’s bargaining position has been compounded by the acute personal pressure on Mrs May. To some extent, the very precariousness of her premiership worked to her paradoxical advantage at the last gasp. When the talks ran into trouble over the Irish border issues, the EU could have told Britain to go away and come back with some fresh ideas in January. European capitals pressed their negotiators to help get Mrs May safely to the end of this particular rollercoaster for fear that she might be toppled. They may find her a tricky customer, but at least she is a known one and they can think of worse people to find on the other side of the table. Their despair at the thought of having to deal with Boris Johnson was the foreign secretary’s most important contribution to the week.

It is worth stepping back from the frenzy to gain a longer and cooler perspective on what has unfolded since the negotiations in Brussels commenced in June. At that point, leading Brexiters were still peddling their fantasy that March 2019 was a feasible date to achieve both a new trade deal and a “clean-break” Brexit that sets Britain free of every EU rule and regulation. The government slowly realised that this was simply delusional and conceded that formal departure would have to be followed by a “transition period”, during which Britain will continue to trade as if it is still a member of the EU at least until 2021. With the important difference that Britain will continue to be subject to EU law without having any say about what those laws are. Britain will go from being a rule-maker to a rule-taker. This will include an continuing role for the European court of justice in Britain’s affairs which will endure deep into the next decade, another of Mrs May’s “red lines” that have faded to a blush pink.

Facebook Twitter Pinterest ‘Michael Gove could give tutorials in how to be oleaginous to Uriah Heep.’ Photograph: Peter Nicholls/Reuters

The other very obvious area where the British government has had to concede is over the money. The claim made during the referendum that quitting the EU would produce a massive windfall, including a fantasy £350m extra a week for the NHS, was long ago exposed for the lie it always was. The hardline Brexiters then fell back on a position of saying that Britain shouldn’t pay a red cent by way of a divorce payment. Some of their number even contended that the EU ought to be paying Britain for access to our markets. Those with a better grasp of where these talks would end up reckoned that a net payment of around €40bn was the likely cost of the divorce settlement. That figure was first mentioned in this column back in July. David Davis jeered that this number was “made up”. Mr Johnson scoffed that the EU could “go whistle”. Now the government says it expects Britain to be paying something of that order, possibly rather more, as “a fair settlement of our obligations”. In the end, even the cabinet’s most fanatical Brexit zealots have been forced to bow to the raw truth that this sum, large as it may be, is relatively small compared with the calamity that would be inflicted on the British economy by a car-crash Brexit.

So how can anyone really be happy? Those who hope for one of the softer versions of departure – a group that includes the pragmatists in the cabinet, the majority of MPs and most businesses and trade unions – are relieved because they think this agreement reduces the danger of a catastrophic “no-deal” Brexit. Mrs May is happy because she has bought herself some more time at Number 10. When it looked as though the talks would fail, some serious players in the Tory party were predicting that it really could be curtains for her. For her, any deal was better than no deal.

The most intriguing question is why the hard Brexiters in the cabinet are now acclaiming Mrs May for making concessions that they would have previously denounced as a betrayal. I think the answer to that comes in three parts. One of the only things to be said for this tortuous and perilous experiment is that it has served as an education for some of the Brexiters, as their illusions have been forced into contact with reality.

I also strongly suspect that the likes of Mr Johnson and Mr Gove have become petrified by what will happen to their reputations if Britain crashes out of the EU and into a nasty recession. In the darker stretches of the night, they must ask themselves how Tory chroniclers will rate them if they are recorded by history as the men who guaranteed a seat in Number 10 to Jeremy Corbyn.

We ought also to remember that, beneath all their blustery bravado, the Brexiters are haunted by the fear that Britain might choose to change its mind. Their overarching goal is to be sure that Britain is formally out of the EU by March 2019. They will swallow anything – principles, pride, groaning plates of their earlier promises – to secure that. They also think, and about this they are right, that the next and more important battle will be about precisely what end state Britain seeks for its future relationship with EU, a subject that, incredibly, the cabinet has yet to debate.

What about the voters? They’ve been rather overlooked while everyone at Westminster has been obsessing over the drama of the negotiations and the intricacies of the deal. To most members of the public, the divorce payment will be the most easily comprehensible element and very likely the most inflammatory – €40bn merely to get permission to talk about a possible future trade agreement? That will sound like a hell of a lot of nurses, schools and marines at a time when the country’s essential services and defences have been squeezed by austerity. A hearty chunk of Brexit voters will surely feel that they have been had.

As for everyone else, the question to keep asking is why our country is spending so much time, energy and money trying to negotiate a deal with the EU that will be inferior to the one Britain currently enjoys as a member. Who can be happy about that?