It wasn’t an accident. It wasn’t naivete. The UK Government knew the Northern Ireland protocol was a mess that would cause problems later, but signed off on it to “get Brexit done”.

That conclusion is becoming impossible to avoid, even without the deafening whispers coming out of Whitehall and Dominic Cummings’ vengeful confirmation that it was a deliberate “fudge” by both sides.

This is government run like a dodgy used car dealership. Sell the dream, paint over the dents and whatever you do, don’t talk about what’s under the bonnet.

Brexit is an object lesson in the dangers of over-promising, one which Scottish observers should continue to watch closely. It would mean “taking back control”, we were told. It would “free” us to act “on our own terms”.

Except we haven’t taken back control and we’re certainly not free to please ourselves. The truth is that in a sophisticated globalised economy, we never can be.

Glittering trade deals? The Australia deal is the only one so far done from scratch, instead of rolled over from pre-existing EU agreements. But it’s more of a trinket, worth a 0.02 per cent increase in GDP over 15 years, and while it could benefit exporters, farmers are alarmed. The NFU fears that importing tariff-free cheap meat produced with lower standards than British meat, as a result of this and similar trade deals with bigger nations, will bring about “the slow, withering death of family farms”. Deep concerns remain about whether the government will uphold Britain’s high food, animal welfare and environmental standards as promised – standards which are supported by consumers – or compromise them in pursuit of deals.

Fishing autonomy? The Scottish Fishermen’s Federation says that the Brexit fisheries deal falls “woefully short” of the promises made for it. Again, any benefit comes at a cost. While technically the UK could exclude EU boats from British waters after 2026, doing so could result in tariffs being slapped on British fish exports to the EU, or on the exclusion of British boats from EU waters.

Barrier-free trade? British exports to the EU have rebounded somewhat from the drastic 40 per cent drop of January, but there have been huge costs, with University of Sussex research suggesting exports worth £3.5bn have had tariffs applied, some because the paperwork that would have made their trade tariff-free was so complex.

And we still haven’t tasted full strength Brexit yet. A host of import controls come into play in January 2022.

Control over our borders? Some voted for Brexit because of it. But again, it has come at a severe cost. Britons now face barriers to seeking work in Europe. Walk into a large hotel and you are likely to find that staffing is tight and Polish, Czech and Spanish accents are eerily absent.

The government, inevitably, blames the pandemic for staff shortfalls, which are causing flowers to rot in fields and some businesses to keep shorter hours, but businesses leaders aren’t daft. The Scottish Association of Meat Wholesalers, Scottish Tourism Alliance, NFU Scotland and Road Haulage Association all say Brexit, along with the pandemic, has caused shortages in meat processing, hospitality, fruit- and flower-picking, and lorry driving.

The Herald: 'Brexit will continue to vex the UK’s political class, and shape the electoral map of England, for years to come'

Supporters of Brexit point to Britain’s swift approval of a Covid vaccine – Pfizer – as a benefit of Brexit. But this is a myth: the UK medicines regulator itself has pointed out that European legislation allows individual member states temporarily to approve vaccines in an emergency.

Boris Johnson has also claimed that Britain hasn’t been able to take advantage of free ports – small areas where normal tax and tariff rules don’t apply – because of the UK’s EU membership, but again, this isn’t true. There are 80 free ports in the EU, though free ports will have greater benefits for a Britain that’s outside of the EU.

New trade deals may present opportunities. As Liz Truss claimed yesterday, they could possibly open up new markets to Scottish exporters. Remainers like me have to try and be positive. But the point is and always was this: that any eventual upsides will come at a major cost. The UK can diverge from the common standards it’s agreed with the EU on the environment and workers’ rights; it can splurge on state aid; but it risks Brussels retaliating with tariffs if it tries.

What is glaringly absent, thus far, is any significant benefit to counterbalance the huge benefits we’ve lost.

As for the Northern Ireland Protocol, the problem is one of the UK’s making, due to the government’s pursuit of a hard Brexit.

There are messy compromises to be done but there is also the real danger of a trade war.

At the root of Britain’s Brexit woes is the complexity of international relationships. We live in a world where no country is truly autonomous any more, if they ever were.

There’s a lesson in all this where Scottish independence is concerned. It’s surely obvious by now that, like Brexit, the process of leaving the UK would be meatball surgery, rather than a clean extraction, entailing a mass of difficulties. The SNP’s determination to rejoin the EU as an independent country would bring benefits, but also downsides. In a mirror image of Brexit, we would be abandoning frictionless trade with our biggest trading partner (the rest of the UK) in order to maximise our trade with other nations (those in the EU).

To cover the glaring problems with its prospectus, the Brexit Leave campaign fell back on empty slogans, emotive claims and even downright lies. There were some echoes with Alex Salmond’s Yes campaign in 2014, when difficult questions about Scotland’s currency and dwindling oil revenues were met with howls of “fearty” at anyone who mentioned them.

The current leadership has signalled its intention to be honest about the upsides and downsides of independence, come another referendum. And there are weighty arguments in favour of independence, principally the democratic one.

But I fear that, like so much of what the SNP says, their noble promises fit under the heading “aspiration” rather than “guarantee”. In the blue-and-white heat of a referendum campaign, people panic, they spin, they appeal to emotions and above all, they present their wildest hopes as firm predictions. They are likely to say what will get them over the line.

Which is why Brexit could be a foretaste of Scotland’s future.

Our columns are a platform for writers to express their opinions. They do not necessarily represent the views of the Herald.