I’VE been saying it since the summer of 2016: Brexit drives a coach and horses through the prospectus for independence put to the Scottish people in 2014. The 2014 campaign was premised on the idea that both Scotland and the rest of the UK would remain in the European Union. That meant several things. The free movement of goods, peoples and services would continue across these islands seamlessly. There would be no European frontier trailing along the banks of the Tweed.

Both states would remain signed up to the same environmental, animal welfare, consumer, competition and trading standards. European citizens in Scotland would retain all of their rights to study, live and work here.

This was practical problem-solving about how the new state would work in practice, but the message had an emotional dimension too: it said independence isn’t a separatist project, but one with an internationalist outlook, comfortable with shared institutions, and the kind of distributed sovereignty most medium-sized countries use to their advantage in an open world.

As the Better Together campaign ­identified in 2014, this position had in-built vulnerabilities. The Scottish ­Government were not, realistically, in a position to ­guarantee an independent Scotland’s ­immediate ­accession to the EU. ­Pro-independence politicians could only make ­reasonable predictions and informed claims about the common interests involved – claims which could easily be presented as weak, speculative and uncertain when compared to the hard political fact of the UK’s membership of the EU.

Project Fear worked hard to put a future independent Scotland behind these imaginary barricades: friendless, isolated, separated. The decision in the rest of the UK to withdraw from the European Union in 2016 means Scots are now confronting a radically different context.

With a week to go in an election ­campaign which may set in train a second referendum process, advocates of independence need to apply their minds to this new reality, and get comfortable talking about some of its uncomfortable implications.

In a more congenial world, the ­negotiations with the Republic of Ireland could have furnished us with an off-the-shelf solution to some of the challenges created by Brexit. The Conservative Party faced a Brexit trilemma throughout the EU withdrawal process: they wanted at once for the whole United Kingdom to jump free of EU common market rules, while maintaining an open border across Ireland, with no new customs barriers or checks in the Irish sea.

We know how these tensions resolved themselves. A physical infrastructure along the 310-mile border from Carlingford Lough to Lough Foyle was avoided, but Boris Johnson was forced finally to accept that sometimes you can’t have your cake and eat it too. Having told ­Unionists in Northern Ireland that a sea border would be imposed “over my dead body,” he bumped the DUP into the ditch instead, the political imperatives of “getting Brexit done” dwarfing any off-stage cries of anguish from the Unionist MPs.

Arlene Foster – turned out of Stormont by her party last week – isn’t the first ­Unionist politician in Northern Ireland to remember what Edward Carson said back in 1921: “I was only a puppet, and so was Ulster, and so was Ireland, in the ­political game that was to get the Conservative Party into power.”

But the SNP now face their own ­trilemma in arguing for independence in Europe. In the best of the best of all possible worlds, they want Scotland to re-join the European Union as a sovereign state, avoid a customs border down the Tweed, and to retain the free movement of people in these islands. Like Boris Johnson, it seems likely in post-Brexit Britain that only two of three goals can realistically be realised. This isn’t Project Fear. It is a simple matter of priorities, trade-offs, and finding a way to explain those in a way which can connect with a majority of the Scottish people. The SNP leadership needs to get more comfortable talking about these issues, because they’re not ­going away.

It is testament to the changing focus of the independence debate that when – in the summer of 2014 – Ed Miliband raised the prospect of the UK Government ­establishing border posts, he claimed to be concerned about immigration rather than implications for trade. “It totally stands to reason,” he suggested, that “if you have markedly different immigration policies, obviously that becomes an issue between Scotland and the rest of the UK.” This was cynical hokum at the time. The Common Travel area is now almost 100 years old, allowing free movement of people across UK, the Republic of Ireland, the Isle of Man and the Channel Islands, dating back to the days of the Irish Free State.

Last year, as the UK Government was amending the Immigration Act to keep more and more foreigners out of our green and pleasant land, Priti Patel lodged amendments to make clear “an Irish ­citizen does not require leave to enter or remain in the United Kingdom”. Reciprocal legislation applies in the Republic.

This followed on from a joint statement by the two governments in May 2019, “recognising the deep and enduring relationship between our two countries,” and “reaffirming the standing of Irish and British citizens in each other’s countries” by virtue of the Common Travel ­Agreement.

The 2019 memorandum commits to maintaining the Agreement “in all ­circumstances”. Practically, it means that Irish citizens in the UK and British ­citizens in Ireland are not required to take any action to protect their status and rights under this old accord, Brexit or no Brexit.

The civil tongue the UK Government can find for the Irish Government and the withering contempt reserved for our own exemplifies the difference independence can make. But given everything the UK Government says it values about the ­Union – the historic ties between us, the long history of free movement – the case for recognising a common travel area in the case of Scottish independence is just as strong as the justification for treating Ireland differently than mainland Europe.

Although the 2014 referendum was full of Nordic fantasias, the relationship between the modern Republic of Ireland and the UK always struck me as a culturally more meaningful parallel for advocates of independence to draw on.

There was a real ugliness implicit in Miliband’s 2014 comments which were in many ways characteristic of the implicit menace the Better Together campaign thrived on. “Stick with us, and you’ll be safe – but cross us? And I can’t say what we’ll do in response. That’s a nice little country you’ve got there. It’d be a shame if something happened to it.” This is the logic of a protection racket – not a voluntary union, truly bound by reciprocal and long-lasting ties of affection.

EXPECT to hear more press headlines soon about how the “SNP can’t guarantee access to the common travel area after independence,” with dark hints from UK ministers that your Scottish-born granny in Corby faces being marched back to the frontier and strip-searched in Berwick. How you can flip from talking about “our precious Union” one minute, to fantasies about rebuilding Hadrian’s Wall the next, is a question I leave to political psychotherapists amongst you.

Making these kinds of arguments might seem like a nifty way of sticking it to the Nats in the short term. But if I was someone who wanted to secure the stability of the United Kingdom in the longer term? The emotional colour of this kind of argument for continuing union would make me queasy.

All of this marks a subtle but important shift – from the endless process-arguments about whether to have a second ­referendum – back to the ­substantive ­merits of independence, in the wake of Brexit and in the aftermath of the ­pandemic. This shift is welcome, but ­advocates of ­independence must be ­prepared for the fact that the political changes in these ­islands since 2014 also change the case for ­independence, ­creating fresh ­challenges as well as new opportunities.

Let’s not shy away from them.