Two very different storms barrelled into Gortmullan last week, one from the west, the other from the east.

Remnants of Hurricane Lorenzo unleashed wind and rain from the Atlantic across the area, a rural pocket of County Fermanagh that marks Northern Ireland’s border with the Republic. “Stay back, stay high, stay dry,” advised the authorities, and residents duly hunkered down. Lorenzo passed without major damage.

Can Boris Johnson’s border plan break the Brexit deadlock? Read more

The other atmospheric disturbance billowed in from England, where Boris Johnson revealed the UK government’s Brexit plan for a hard border between Northern Ireland and the Republic, a potentially chilling prospect for peace and prosperity on the island. The prime minister’s long-awaited proposal sent officials and politicians in Dublin, Belfast and Brussels scrambling for position in the next phase of the UK’s tortuous effort to leave the European Union.

Around Gortmullan, businesses and ordinary people were left wondering if – and where – to seek cover, a dilemma dating from the 2016 referendum result that now thrummed with urgency.

“We’re setting up new companies on both sides of the border,” said Liam McCaffrey, CEO of Quinn Industrial Holdings, which supplies building materials.

Customs checks would be bad enough, but Johnson’s apparent plan to give the Stormont assembly a veto over trading arrangements verged on surreal, said McCaffrey. Power sharing in Northern Ireland collapsed in January 2017 and shows little sign of reviving. “The future of how we trade is to be decided every four years by an assembly that hasn’t sat in three years? Bizarre.”

Such was the challenge of Storm Boris. Perhaps it was hot air, a plan destined for oblivion to be superseded by who knows what. Or perhaps it was a blast of what is to come in a no-deal crash-out, or a deal negotiated in the next few weeks or after a general election. The uncertainty was head spinning.

Jonathan Powell, Britain’s chief negotiator in Northern Ireland from 1997 to 2007, struck an ominous tone. “Be under no misapprehension, there will have to be checks and there will be a hard border which will undermine the basis on which the Good Friday agreement was built in trying to find a way of dealing peacefully with the different identities of the different communities in Northern Ireland,” he wrote in the Belfast Telegraph.

“But the danger I fear for Northern Ireland is that it becomes the mouse as the two elephants – the EU and the British government – mate, and it is Northern Ireland that will lose out in any agreement they reach with very dangerous long-term consequences.”

Facebook Twitter Pinterest Jonathan Powell, former chief British negotiator on Northern Ireland. Photograph: David Ramos/Getty Images

The 310-mile border, drawn in 1922 during the partition of Ireland, bristled with military patrols and fortifications during the Troubles. The 1998 Good Friday agreement and the EU’s single market rendered it invisible, helping to seal the peace.

In Gortmullan – a patchwork of farms, bungalows and hedgerows – there are no road markings to indicate the frontier. Jack McGann, 16, who works at a service station just inside the Irish border, hesitated when asked to identify where the UK began. “I’m not 100% sure. I think it’s over there by the shed, the line goes along the middle of it,” he said, pointing at a derelict structure with a tin roof abutting a road. There are about 300 other border crossings.

McGann has never known customs checks, army searches or terrorist attacks. “My parents told me stories about the hard border. I heard it was tough.”

Eugene McAffrey, who worked at an adjacent service station just inside Northern Ireland, sighed at the mention of Brexit. “It’s occupying the mind of everyone that walks in here. How could it not?”

In a pub at Derrylin, a few miles up the road, Shane McBrien, a painter, seethed at the Democratic Unionist party for endorsing Johnson’s plan. “Any physical border will bring back bad memories. It’s just going backwards.”

His brother, Eugene, said a hard border would compound the fact that Brexit ignored the will of most Northern Ireland voters. “The north voted to remain. We’re being tossed out of the EU. We’ve no say.”

Applications for Irish passports from Britain and especially Northern Ireland continue to surge, reaching 85,517 by the end of August, outpacing the 79,513 for all of 2018, according to figures released last week.

A complex web connects the economies on both sides of the border. Trade in goods is worth about £5.2bn. About a third of Northern Ireland’s goods and services exports are sold to the Republic, while about a quarter of its imports come from the south.

Downing Street says electronic paperwork and a “very small number” of physical inspections at traders’ premises would limit disruption. Farmers and business leaders dispute that. Some warn of disaster.

Diageo, which makes Guinness and Baileys, estimates a hard border could cost it £1.3m, based on an estimate of an hour’s delay for each of the 18,000 beer trucks that traverse the border each year. Smaller businesses with tight margins could face ruin. “My business and family need flexibility,” said Gerard Crowe, a butcher in Ballyconnell, inside the Republic. “But what’s coming won’t give flexibility. We’ve been through all that before and we don’t want it back.”

Dissident republicans have hailed Brexit – and specifically the prospect of a hard border – as a historic opportunity to revive an armed campaign. Public support for that seems negligible and attacks remain sporadic.

But even before Johnson unveiled his plan there was a sense of the police battening down the hatches. Last Monday Irish police established a new armed support unit in Cavan, which borders Fermanagh, to combat a surge in criminality and to prepare for Brexit.

The Police Service of Northern Ireland is planning to deploy hundreds of officers on Brexit-related operations and wants £40m to recruit 300 additional officers. Simon Byrne, the PSNI chief constable, said he told the prime minister in a recent video call that his officers will not police any customs checkpoints or “be dragged” into another type of policing. A bold assertion. Northern Ireland’s history shows a hard border exerts a powerful drag.