How a War Helped Ease a Rift Between Britain and the E.U.

LONDON — It took the invasion of a sovereign nation, the bombardment of its cities and the continent’s biggest security challenge in decades to make it happen. But for the first time in years, Britain and the European Union are working together again.

On Friday, Britain’s foreign secretary, Liz Truss, attended a meeting of European Union ministers in Brussels to discuss the crisis in Ukraine, a move that, in pre-Brexit days, would have been routine, but one that now underscores a striking rapprochement.

In the poisonous aftermath of Britain’s exit from the European Union, the relationship between the two sides degenerated into discord, distrust and open sniping.

But confronted with the war in Ukraine, and resulting issues that are several orders of magnitude graver than rifts over fishing rights or the movement of sausages, the chasm opened up by Brexit is beginning to narrow.

“In the two years I have been here, I don’t think I have seen such intensity and quality in our relationship as I have in the last two weeks,” said João Vale de Almeida, the European Union’s ambassador to Britain. Ms. Truss’s attendance at the Brussels meeting was “very meaningful and symbolic,” he added.

The new mood of cooperation points to the possibility that, after years of division and feuding, the two sides might be starting to put Brexit behind them. When asked about the significance of Ms. Truss’s visit to Brussels, a spokesman for Prime Minister Boris Johnson of Britain said that it showed that Britain was working very closely with European partners. He added: “What we have been able to demonstrate to Putin is a strength of unity on this, moving with purpose.”

Since Russia launched its invasion more than a week ago, Britain has moved in step with the European Union, the United States and other allies to introduce sanctions intended to cripple the Russian economy, and analysts have noted the changed atmosphere.

Almost six wearying years after Britain voted to leave the European Union, even the most hardened Brexit supporter knows that Moscow is a bigger threat than Brussels, and even the most hostile critics of Britain in Europe understand that sanctions against Russia work better with British economic heft behind them.

“The E.U. and the British are looking at the bigger picture and at our fundamental interests and finding a considerable degree of alignment,” said Sophia Gaston, the director of the British Foreign Policy Group, a research institute.

“The Russian invasion is such a profound threat to the European neighborhood that the West has risen to the challenge. What has happened over the last 10 days has been an extraordinary coming together to such an extent that it could become a good news story for the West,” she added.

Nonetheless, Ms. Truss’s decision seemed to surprise some in Britain, generating a headline in the Daily Express newspaper, a pro-Brexit champion, that read: “U.K. back in Brussels! Truss to join special EU council despite Brexit as Putin sparks unity.”

This was not the sort of scenario envisaged last year when Mr. Johnson published his strategy for a post-Brexit “global Britain,” which stressed British ties with the United States, and with Asian and Pacific countries, but which said very little about cooperation with its European neighbors.

To the annoyance of France, Britain as part of that process entered a trilateral security pact with the United States and Australia, in the process depriving the French of a lucrative submarine contract.

And in a parliamentary committee last year Mr. Johnson said that the days of “the old concept of fighting big tank battles on European land mass are over.”

Yet in recent weeks both Mr. Johnson and Ms. Truss have switched their attention to the European continent, making several visits to Baltic States that border Russia, as well as to Poland — NATO nations that are also members of the European Union. That means that many of their policies, including economic sanctions, are coordinated in Brussels.

On Friday, as she arrived at the meeting in Brussels, Ms. Truss said that Britain was working with the European Union, the United States and Canada to secure the “toughest possible sanctions,” adding, “we want to see more.”

And while some in Britain initially doubted that their continental neighbors would rise to the challenge posed by Moscow, they have been disproved by the extraordinary shift in Germany’s foreign policy, including its decisions to suspend the Nord Stream 2 pipeline, to increase military spending and to send weapons to Ukraine.

“Germany has taken courageous steps,” Ms Truss told lawmakers this week. “It has transformed its energy policy and its defense policy, and we have seen a huge rising of public opinion right across Europe.”

There have been differences over sanctions, with continental European nations unable to wean themselves quickly from their dependency on Russian energy or to cut off some of the mechanisms of paying for it. While Britain has pushed harder on banking measures, it has struggled to shake off the influence of Russia’s oligarchs on British life.

Nonetheless, there has been relatively little point scoring, even between London and Paris, whose ties have been particularly fractious, a sign — perhaps — of a more cooperative, post-Brexit, world. “I think we saw both sides saying, ‘here we can appeal to our better angels and keep things in a more sober space,’” Ms. Gaston said.

Even before the invasion, relations between Britain and the European Union had improved after the resignation from the cabinet of David Frost, who was Mr. Johnson’s Brexit negotiator. His hard-line negotiating tactics made him few friends in Brussels during tortuous talks over a contentious part of Mr. Johnson’s Brexit deal that governs trade between mainland Britain and Northern Ireland.

Responsibility for negotiating changes to the agreement, known as the Northern Ireland protocol, went to Ms. Truss, and while she so far has not changed policy, her tone has been seen in Brussels as more constructive.

Responsible for foreign policy, Ms. Truss is sensitive to the wider international picture including President Biden’s desire not to do anything that could risk the fragile peace process in Northern Ireland.

So while Ms. Truss has not ruled out invoking an article that would suspend part of the protocol, doing so during the height of the Ukraine-Russia crisis seems unlikely.

One question is whether the truce between London and Brussels can outlast the war in Ukraine.

Mr. Vale de Almeida said that the crisis “only proves how much we have in common — even after Brexit so much unites us,” but added: “For cooperation to work better, we need some structure and some sort of permanent mechanism of cooperation.”

The idea of some sort of security pact with the European Union was rejected by Britain during the Brexit negotiations. But it no longer seems so unlikely, even if some in Britain argue that ad hoc arrangements have worked adequately to coordinate sanctions.

Ms. Gaston said that the invasion of Ukraine had been such a seismic event that its full implications will take time to unfold. Europe also faces political uncertainties with the arrival of a new German chancellor, Olaf Scholz, a presidential election looming in France and questions about whether Mr. Johnson can survive a scandal over parties during a coronavirus lockdown held in Downing Street.

But given the history of recent years, it would be unwise to take any cross-Channel rapprochement for granted, even one incited by the war in Ukraine.

“It has been transformative, and we have a better chance that a culture of cooperation will become embedded,” Ms. Gaston said, “but I don’t think we can assume that it necessarily will.”