Just when the whole of democratic Europe should be pulling together to counter the threat from Vladimir Putin’s Russia, a major rift between the European Union and Western Europe’s leading military power — the United Kingdom — has been widening. The problem is Brexit. 

The U.K. is threatening to rip up part of the withdrawal deal it struck with the bloc just over two years ago on the grounds that it’s working badly in Northern Ireland. Trade between the British territory and the U.K. mainland has been disrupted and the regional governance of the province has broken down.

Some fear that this has imperiled the U.S.-brokered Good Friday Agreement, a peace deal approved in 1998 that ended decades of violent struggle over British sovereignty in Northern Ireland.

Trading with the EU has certainly become a lot more complicated after Brexit. Just ask Archie Norman, chairman of the giant British food and clothing retailer Marks & Spencer. In an interview with the BBC, Norman revealed what’s involved in sending just one truckload of goods across the Irish Sea to the Republic of Ireland, an EU member state.

“Wagons have to carry 700 pages of documentation,” he said. “It takes eight hours to prepare the documentation, some of the descriptors have to be written in Latin, has to be in a certain typeface, it takes 30% more driver time. So it’s highly bureaucratic, very onerous and pretty pointless.”  

It’ll be even more pointless, he said, when the Brexit grace period ends and he faces the same hassle sending goods across the Irish Sea to the British-owned northeast corner of the island of Ireland.

“Quite a lot of product simply wouldn’t get to Northern Ireland, and what does go there would be very, very costly,” he said.  

For most nonfood products arriving in Northern Ireland from the British mainland, the Brexit grace period is already over, and a wide swathe of goods from what is called Great Britain, or GB, has already been squeezed out of the Northern Ireland market.

“We’ve not brought a plant in from GB this year. It’s just too much hassle,” said Robin Mercer, who runs the Hillmount Garden Centre in Belfast.

Instead, he’s had to buy his plants from further afield — from EU countries like the Netherlands and Italy, where there are different weather and soil conditions. He believes the British plants are healthier and, after traveling shorter distances, arrive in better condition than their continental counterparts. He would prefer to import British plants.  

“Oh totally,” he said. “We’ve worked with firms for 20, 30 years from GB. But it’s just so much paperwork now, so much hassle.”

More than 200 companies based in Great Britain have stopped supplying Northern Ireland because of that hassle, according to the U.K. government.

But all these difficulties, said Mattia Di Ubaldo, a fellow at the U.K. Trade Policy Observatory, are the inevitable result of Brexit.

“These checks are what typically applies to any third country that tries to import things into the EU,” he said. “The EU has to protect the integrity of the single market. They cannot allow a border where products could leak into the European Union without being subject to the checks.”

And, he said, those checks have to take place when the goods enter the island of Ireland. They cannot take place between Northern Ireland and the Irish Republic.   

“Avoiding a border in the island of Ireland was necessary to protect the peace process,” he said, echoing the view of the large minority in the British province that wants a united Ireland.

That view of the border checks is shared by the government of the Irish Republic, the European Commission in Brussels and the U.S. administration, which all believe that checks between Northern Ireland and the Irish Republic would undermine the Good Friday Agreement.

The trouble is that putting the border checks between the province and the rest of the U.K. instead — under an arrangement called the Protocol — has enraged many so-called unionists who want Northern Ireland to remain British. They believe that the Protocol itself undermines the Good Friday Agreement.

“The Protocol must go,” said Sammy Wilson of the Democratic Unionist Party, which is now refusing to take part in the assembly and power-sharing administration set up in the province by the Good Friday Agreement.

“The Protocol is the poison in the system at present. There is no consent for the Protocol among any of the unionist representatives,” Wilson said. “The Good Friday Agreement requires the consent of both communities in Northern Ireland when it comes to any controversial or any important decisions.”

The U.K. government in London agrees and has pledged to introduce a bill enabling it to suspend unilaterally parts of the Protocol if the EU doesn’t agree to radical changes. Brexit-supporting lawmakers like Peter Bone welcomed the move.

“The only way you’re going to get the EU to come to the negotiation table and really negotiate with you is if you threaten them with that bill,“ he declared in a rowdy parliamentary session.

But Opposition spokesman on foreign affairs Stephen Doughty accused the government of bad faith, of threatening to tear up a treaty that it signed just over two years ago.

“Britain should be a country that keeps its word. The rest of the world is looking at us and wondering whether we’re a country they want to do business with,” he said.

In the United States, Nancy Pelosi, speaker of the House of Representatives, warned that Congress wouldn’t agree to a free trade deal with the U.K. if the Brits ripped up the Protocol. The European Commission hinted at a trade war with the U.K. over the issue, and the U.S. State Department deplored this rift between the allies when they should be united behind Ukraine.

The EU said it is prepared to contemplate some changes in the Protocol but that it suspects the U.K. is trying to wriggle out of this key part of the withdrawal deal.

Meanwhile, the U.K. countered that the Protocol specifically acknowledged that the measure could be set aside if it proved unworkable. And both the political paralysis in the province and the trade disruption between Northern Ireland and Great Britain, said the government, show that the Protocol isn’t working to the satisfaction of the unionists.