As Boris Johnson journeyed back from this week’s desperate trip to Germany and France, he might have reflected on his hero Churchill and those “dreary steeples of Fermanagh and Tyrone”. Somehow those totems of Britain’s archaic colonisation of Ireland refuse to release their stranglehold on British politics. And here was Johnson at their mercy, being lectured by Angela Merkel and Emmanuel Macron on how to govern them. It was intolerable.

Johnson got no joy in Berlin or Paris. Merkel’s meaningless 30-day “talks” period was greeted with ecstasy by his Tory press claque. But Macron merely pointed out that nothing had changed. The steeples were still there, telling London what not to do.

The 1922 partition was meant to be temporary. It has long been an agony for Britain

As of now, the Downing Street cabal of Johnson, Dominic Cummings and Michael Gove may have a plan, however costly, on how to crash out of the European Union’s customs union. They still have no plan for Northern Ireland. There, no deal promises the ultimate horror, of a return to policing the 1921 partitioning of Ireland, this time with some ramshackle arrangement of border posts, customs checks and massive evasion.

The partition was meant to be temporary. It has long been an agony for Britain, leaving it with an overseas province divided on religious lines and simmering with hostility towards and from its neighbour in the south. Two decades ago the Good Friday agreement appeared to ease the tension. Economic convergence replaced political antagonism. At long last, Northern Ireland generated good news, not bad.

A soft Brexit offered no change to this state of grace. It honoured the economic union of Ireland by keeping the UK within the customs union and single market. But Johnson wants a hard Brexit. In his letter to the EU this week, he openly trumpeted “divergence” in trading standards, regulations and tariffs within the island of Ireland. He seeks to liberate Northern Ireland, as an indissoluble part of the UK, from what he sees as intolerable intrusion by outsiders in UK laws and regulations. He somehow believes these intrusions would not apply to trade with China or the US. He disagrees with Macron, that British free trade with China or America would lead to more insistent “vassalisation” than anything from Brussels.

To avoid fixed barriers across 300 miles of lanes and cart tracks in Northern Ireland, Johnson now imagines a “virtual” border, bureaucratic and technological, pulled back from the frontier to a digital wonderland of trusted traders, certificates, surveillance cameras, inspection points and passport checks. These would be located somewhere between the Irish border and Belfast airport and docks. The same checks would have to apply to the £3bn a year of British goods moving south to Dublin and the EU. Trucks would flow as now, but the customs would catch up with them later on, to monitor animal health and food standards, collect tariffs and somehow chase after those evading new limits on EU immigrants.

All involved in these negotiations – from Merkel and Macron to the humblest border official – say the same. What is Johnson talking about? A border is a border, wherever located. Trade divergence is divergence, a tariff is a tariff and a check a control. These are frictions, barriers to trade, whether concrete or virtual. Could Johnson please cite just one comparable example of his border, as the EU tariff expert Sabine Weyand asks, “anywhere on Earth?” Or is this just posturing for the rightwing press? Most people I know do not understand the Irish backstop. They treat it like the Schleswig-Holstein question, so impenetrable as to be merely a badge of tribal machismo – for or against. That “question” too was over a provincial border, and it took Prussia to war twice with Denmark. Borders are real. They are not just gates. They mark out the geography of sovereignty. They need guards and they draw blood.

The Irish backstop is not a guarantee, as the EU calls it. It is a demand that London acknowledges its blatant inconsistency. Northern Ireland cannot both remain in commercial union with the rest of Ireland and yet join whole-heartedly in Johnson’s new WTO regime for Britain. There is no point in kicking this can down the road. Britain should confront the contradictions long inherent in Northern Ireland’s ambiguous status. The EU is saying to Britain, grow up.

In the present context of hard Brexit, this can only lead in one of two directions. The EU can back off and indeed agree to kick the can down the road. It can pretend to time-limit the Irish backstop and see what happens. If that might reactivate Theresa May’s withdrawal agreement, permit Brexit in October and let tempers cool for a negotiation of a new trade deal in the transition, it might be worth it. But in reality it would just postpone the agony, and the EU clearly has no intention of doing that, however much Johnson puffs and blusters. Or Johnson could defy the DUP and agree to a separate, soft-Brexit status for Northern Ireland in relation to the south. This would accept some border arrangement down the Irish Sea, with a de facto border at sea ports. It would eliminate any need for the backstop. Brexit could proceed as Johnson promised on 31 October.

One thing is heavily on the side of the second option. Northern Ireland did not vote to leave but to remain, and by 56%. Since then polls by LucidTalk are unequivocal. Sixty percent of Northern Irish voters are for some continued customs link to Ireland, explicitly separate from the rest of the UK. This surely is a sign of Northern Ireland’s evolving maturity. The province is a sufficiently distinct political entity, like Scotland, to be entitled to self-determination. If that brings it closer to Dublin, so be it.

This must be the moment for Johnson to call the DUP’s bluff. If Britain really is to crash out of the EU in two months, there will have to be border controls somewhere round the shores of the Irish Sea. The EU cannot let Ireland become open country for smuggling. Nor can Britain accept a flood of incoming EU food when its own exports are subject to EU tariffs.

A majority in the north is clearly ready for exceptional status. Northern Ireland would remain in the United Kingdom. It might be drawn more into the orbit of the south, but that has already been the consequence of the Good Friday agreement – and a welcome one. It is better than a slither back to super-partition, as horribly echoed in this week’s paramilitary shooting in Belfast.

Northern Ireland must one day free itself from the shackles of its past, shackles that still drearily hang round its political neck. It cannot be too much to imagine a beneficial legacy of Brexit being the liberation of the province from this anachronistic incubus, a legacy that steers all of Ireland on a path, however slowly, towards a stable and contented union.

• Simon Jenkins is a Guardian columnist

• This article was amended on 28 August 2019. Because the results of a LucidTalk poll were misread, an earlier version mistakenly said that 40% of the Unionist community were happy with a border down the Irish sea. The poll found that 27% of Ulster Unionist supporters, 14% who voted for other unionists or loyalist candidates and 5% of DUP voters agreed that there should be a backstop. Looking just at the Unionist community overall, 15% said there should be a backstop.