European Union's chief Brexit negotiator Michel Barnier holds a news conference after a General Affairs Council in Brussels, Belgium. File/Reuters

Anyone should readily understand why any Scot would be wanting independence just now. As a nation, Scotland rejected Brexit decisively. Just to remind you, the 2016 result was 62 per cent to 38 per cent for Remain – as it happens a much bigger rejection than the margin by which the English embraced the proposal (53 to 47 per cent).

After that, as the process ground on, the wishes of the Scottish government about Britain’s new relationship with Europe were ignored, if not derided. It did not feel like a relationship of equals. Powers were anyway repatriated to London from Brussels. Now Brexit is already decimating parts of the Scottish economy. And it is a very long time indeed since the people of Scotland voted for a Conservative government. Boris Johnson is the very epitome of a quasi-colonial overlord, making rare visits north of the border just to mark his territory, to cock a leg on Scottish national aspirations. No wonder the whole unhappy experience of the last few years has given a fair old shove to the nationalist cause.

As with Brexit, ironically enough, a larger majority of the people of Scotland would presently like to regain their national sovereignty and “take back control”. Brexit has, predictably, made Scotland keener on independence than it was in 2014; and it is perfectly clear that constitutional circumstances have altered radically since the last vote on the matter in 2014, narrow enough to lack lasting authority. Besides, there was nothing in any legal document about the first Scottish independence referendum being a “once in a generation” decision. It was just a political slogan, and politics change.

The problem, though, is that Brexit has made it far more difficult for independence to work as a proposition. In practical terms, if a free Scotland wants the kind of free and easy movements and relationship with England, Northern Ireland and Wales we all currently enjoy, then independence makes that impossible. Ask anyone in Northern Ireland, a relatively benign version of what happened. If the UK had stayed in Europe after 2016 – as David Cameron riskily promised the Scots in 2014 – then things would be relatively easy for an independent Scottish sovereign state. All parts of the remaining UK and Scotland would be still integral parts of the EU Single Market and the EC customs union. There’d be free movement of people and goods, and completely frictionless trade in services such as banking, and no need for any real border between Scotland and England. Even if Scotland adopted the euro there’d be no necessary reason for an economic border. Independence would have been emotionally traumatic, but economically seamless.

Now, though, Scotland would be faced with the same kinds of choice that faced the UK, and indeed the EU, after the Brexit vote. Would an independent Scotland have a hard or soft border with England? Would it wish to be a full member of the EU single market and customs union, or the UK equivalents? What about a common travel area, as Ireland and the UK still enjoy, uniquely?

If Scotland seeks to be a full member of the EU, enjoying all the benefits and global clout that brings, how will it run its economic border with the UK? Or, more accurately, given that the border of an independent Scotland with England would also be the second land border between the EU and what remains of the UK, what does the EU want it to be? Will it be a world where English tourists have their ham sandwiches confiscated at the border on the A74? Will the trains stop for a passport check as they cross the border? And who decides that – Brussels or Edinburgh? If you’re unlucky enough to have been born in England, but your mum is Scottish, can you get an EU passport too?

Who, even, will be doing the negotiations with London? Initially, it would have to be Edinburgh, but as EU membership for Scotland became closer to reality it would be a matter for Brussels as well. We could, in other words, see the return of Michel Barnier to add some heft to Scotland’s negotiations, just as he did to protect Ireland’s interests? It would be very messy and the flow of goods north and south would be inevitably slowed, probably permanently. Sailing or flying direct from Scotland to the European heartland would surely add costs and reduce the reliability of supplies? Like it does for Ireland, England represents a practically unavoidable land bridge to Europe, as well as a huge market in itself, and getting around it will not be easy. Services too would be badly disrupted if the rest of the UK refuses to automatically recognise Scottish (ie EU) professional qualifications and other standards (and vice versa).

No doubt, Nicola Sturgeon will have a plan for all this, but the terms of Scotland’s separation from the UK can’t be settled unilaterally or in advance. Just as no one could be sure about where Brexit would eventually end up, and Brexit meant different things to different people, so too is it impossible to say what the new relationship with England and the rest of the UK ends up like. As I say, it wouldn’t actually be entirely up to the Scottish government either. Ms Sturgeon and the SNP would not be able to publish a pamphlet and say “this is how it’s going to be” because she cannot know for sure.

The harsh reality of hard Brexit has revolutionised the terms of the debate on Scottish independence since 2014, when all concerned could assume continued EU membership across the British Isles. Politically, Brexit and its aftermath has made independence more attractive than ever for many Scots (though still with a substantial Unionist minority); but economically it is presenting near-insurmountable obstacles to trade and working across the border. Of course, we could all pretend that it is perfectly possible with goodwill all round for Scotland simultaneously to be part of the UK customs union and single market, and also part of the EU customs union and single market. It is, though, the kind of magical thinking that everyone indulged in during the early stages of Brexit, and Northern Ireland provides the living proof that you cannot have your cake and eat it. Anyway, it will be up to Brussels as much as Scotland to decide what the new border looks like.

Scotland can certainly become a nation again, and the 28th member of the EU, just as Ireland is. But there will be a considerable price to pay to regain sovereignty, just as there was and will be for Britain, post-Brexit. Indeed, the practical obstacles to a working arrangement on the Scottish may prove practically insuperable in practice. The prospect of them might persuade a decisive number of Scottish voters that they cannot face the hassle.

In the very long run, Scotland will make its own choices and prosper and become a nation at ease with itself, at the centre of the interlinking circles of the EU, the Commonwealth and (presumably), Nato, just like Britain used to be. In the short to medium term, though, the Scots will be poorer, but happy. Just like the English.