(Bloomberg) -- From his restaurant at an old Nazi military bunker on Jersey’s rocky northwest coast, former fisherman Sean Faulkner makes a prediction: “If they don’t get their own way, they’ll be back.” 

Like his fellow islanders, Faulkner, 66, had just watched French fishing vessels stage a protest over changes in access to waters following the U.K.’s departure from the European Union. The standoff prompted Britain and France to deploy warships in the strip of sea that separates them. Billed as a game of chicken by U.K. tabloids, the same press rejoiced when the French went home.

So while the immediate danger was defused, the sight of a naval confrontation near an island of 100,000 inhabitants was a reminder of the real-life consequences of an acrimonious divorce and why it’s such populist political catnip.

The sudden escalation turned a local economy primarily based on financial services into a post-Brexit theater of the absurd, and though few in the outside world can locate Jersey on a map, the fight is over a lot more than the mackerel, pollock and crab off its shores.

As part of the Channel Islands, Jersey is neither in the EU nor officially in the U.K. It is a self-governing British crown dependency 14 miles away from France that relies on Britain for its defense. People there had no say in Brexit, a topic that consumed politics and markets.

Fish was the last sticking point in talks and one that resurrected hostility between two neighbors that have taken turns being bitter enemies and strategic allies over centuries. So Jersey, almost by accident, got ensnared in the fraught cross-Channel relations in recent months that has involved everything from customs bureaucracy to coronavirus vaccines.

“Our cultural ties go back a thousand years,” said John Le Fondre, Jersey’s chief minister, who has been working with the U.K. government and European Commission on resolving the fishing problem. “This slight difficulty is saddening.”

The latest clash came after France’s maritime minister, the daughter of a Brittany fisherman, suggested the government could cut off electricity supply to Jersey if the country’s grievances over fish weren’t addressed.

The Brexit deal was that EU boats would still allowed to fish in U.K. waters for years though their access would need to be curtailed and also there would be a lot more red tape. There are delays in getting licenses and the pandemic didn’t help.

Annick Girardin’s words triggered a series of unintended consequences, according to French officials speaking on condition of anonymity. They said they were surprised how quickly the situation escalated and worked the back channels to smooth things over. In Paris, the government was left navigating between appeasing the U.K. and publicly showing support for embattled fishermen. 

The showdown also had its political uses. U.K. Prime Minister Boris Johnson enjoyed a wave of positive headlines with the Daily Mail labelling the retreat of the French fishing fleet as “Le grand surrender.” For French President Emmanuel Macron, some saber-rattling at the British is no bad thing when you face a challenge from the far-right leader Marine Le Pen.

Amassing around Jersey’s 16th century Elizabeth Castle beside its main harbor, the 60-strong flotilla was met with a military history re-enactment enthusiast firing a musket from the castle’s ramparts. France last tried to invade Jersey in 1781 during the American Revolutionary War, the defeat of which is celebrated by various monuments throughout the island.

Yet screaming headlines of a potential blockade and the cutting of power supplies also carried a sinister undertone for some residents, given how they suffered food shortages when the island was occupied by the Germans during World War II. On Sunday, it celebrates the liberation from the Nazis.

At issue now is whether the spat can be quickly resolved, after French boats argue they were wrongly denied access and the European Commission accused the U.K. of breaching the terms of the Brexit deal. Caught in the middle, the Jersey government said it believes there are practical solutions.

The value of the fishing at stake is a rounding error for the French, U.K. and Jersey economies, but it’s an emotive issue. Disagreement over fish almost derailed the entire trade deal between Britain and the EU, before a compromise was reached at the 11th hour on Christmas Eve.

“It’s not just about a few mackerels,” the EU’s chief Brexit negotiator, Michel Barnier, wrote in his recently published diary about the trade negotiations. “It’s about men and women who live dangerously, courageous communities, who sustain coastal territories.” A last-minute British proposal on fishing introduced just days before a deadline ran out on producing the trade and cooperation agreement was a bluff, he said, a document “filled with traps, false compromises and backsliding.”

Fishermen in Jersey have been particularly affected, with Faulkner having lost up to 50% of his sales from not being able to export to France due to the rising political tensions and new red tape. Jason Bonhomme, another fishermen, was unable to land his catch of cuttlefish in Carteret because an intimidating group of French fishermen stopped him at the quay.

Brexit has been “carnage,” one person who fishes lobster and crab around Jersey said, who asked not to be identified. They used to export their catch in France, but now they must try to sell it all locally. 

Some zones remain closed, which means boats are wading into other waters. French fishermen will argue there are also other unresolved factors in play, such as how the fish reproduce closer to their warmer coastline before migrating closer to England at the adult age when they become prize catch.

A quirk of the dispute is the rich seam of French heritage that runs through Jersey, which is best known internationally for its potatoes and cows. Many of its road names are in French and Jerriais—the local dialect that is still taught in the island’s schools, though few people speak it natively—is closely related to French.

It’s also not the first time French boats have made a statement around Jersey: In 1998, some Frenchmen briefly captured the Minquiers, a small group of rocks and islands belonging to Jersey off its south coast where fishermen often land.

For all the controversy, years of fishing together in shared waters means many Jersey and French fishermen are friends and they don’t want to see the dispute get out hand. Many Jersey people have French blood in their ancestry and the island has long enjoyed good relations with its closest neighbor, the lobster-fisher said.

As one person put it: “We don’t want to start a war with the French.” 

©2021 Bloomberg L.P.