The DUP is right to be worried that the backstop threatens the Union

The Northern Ireland backstop remains the sticking point for May’s Brexit deal – the potential hiving off of a constituent nation of the UK into a different customs and regulations regimen with no assurance on when it might end. To avoid a hard border on the island of Ireland, Northern Ireland would still sign up to EU customs rules, with the rest of the UK, and effectively be in the Single Market until “alternative arrangements” are in place.

So why is this important? Why does it matter if produce coming over the Irish sea is subject to a few checks? Well, that’s because, historically speaking, customs unions are almost always a prelude to political integration. That frightens Unionists in the North, and they are right to be worried, as Walter Ellis wrote for Reaction a couple of weeks ago: “Brussels will make the rules and Dublin will oversee the practicalities. London will gradually withdraw behind the newly-drawn border down the Irish Sea.”

After all, our very own precious Union began its life in a debate over customs arrangements. In 1705, the House of Commons passed The Alien Act which empowered commissioners to begin negotiations for England and Scotland to be brought together in Union. If the discussions proved unsuccessful by Christmas Day of that year, all major Scottish exports to England would be suspended and all Scots treated as foreigners in England (a no deal scenario!). Two years after the Scots were forced to the negotiating table, the Treaty of Union passed through the Edinburgh parliament, its first article advertising, in grand style: “THAT the Two Kingdoms of England and Scotland shall … forever after be United into One Kingdom by the name of GREAT BRITAIN.”

The Union was in no way inevitable, conceived as it was in a spirit of chicanery, high intrigue and huckster-style politics, and it proved a fragile settlement in its first decades. Jacobite sentiment, loyal to the Stuart dynasty and rooted in Episcopalian suspicion of the renewed interest in Presbyterianism brought in by the “Glorious Revolution” of 1688 remained a potent rallying cry in the early 18th century, only resolved after the total defeat of Jacobite forces at Culloden Moor in ’45.

Unionism articulated a complex meld of aspirations. Upwardly mobile Scots wanted to show that their little country could assume its place in the history of the world. Its elite schools embraced the classicising idealism of the Scottish Enlightenment, which had burnished Edinburgh’s reputation as a European capital. Schools like the Edinburgh Academy, founded in 1824, were founded on the ideals of Athens, Sparta and Rome. Scotland could, they thought, be more than its sectarian divides between Kirk and Catholicism, and more than the romantic Jacobite mythos.

The Unionist creed allowed Scotland to make a relative success of the vast social changes of the nineteenth century – to negotiate rapid industrialisation, make the most of burgeoning trade over the English border and with the rest of the world, and to redeploy the Highland population – “cleared” from their land to make way for profitable sheep farming and kelp harvesting – in new urban centres.

On this the Brexiteers are right – economic rules do matter. Where trade and customs arrangements are made, and how they get political legitimacy, really are consequential. The backstop could well accelerate centrifugal forces that are already pulling the Union at the seams. Northern Ireland is going through demographic changes that could fairly quickly build a majority for union with the South, and within the next ten years, the electorate looks set to be 55 per cent Catholic and Nationalist, with young voters of both Protestant and Catholic persuasion overwhelmingly supportive of reunification.

The DUP knows this. The “meaningful vote” on May’s deal, now to be held during the week commencing 14th January, could well determine not just the direction of travel for the UK for the next few years, but lead to the slow-motion break-up of the Union as it exists now.