The United Kingdom and the European Union recently unveiled a revised rulebook for trade in Northern Ireland, which had become a major sticking point in post-Brexit diplomacy.

After the U.K. left the EU in 2020, Northern Ireland remained in the EU’s single market for goods and was subject to its laws. This avoided the need for politically sensitive checkpoints on the land border with the Republic of Ireland. But it disrupted trade with the rest of the U.K. and alarmed Unionists who prize close economic and political ties with the British mainland.

On Feb. 27, U.K. Prime Minister Rishi Sunak and Ursula von der Leyen, president of the European Commission, shook hands and hailed their agreement as the best way to keep trade flowing across land and sea borders. It involves sending U.K. goods into different custom lanes in Northern Ireland depending on their final destination.

What was remarkable about this carefully choreographed announcement was what happened next – or rather what didn’t happen. No cries of betrayal from pro-Brexit U.K. lawmakers. No rancor in European capitals over British backsliding. Even the Unionists held fire so they could study the details.

I covered U.K. politics in the chaos and confusion that followed the 2016 referendum, and this feels like a new chapter. It was a newsworthy event that got everyone talking. But it was framed mostly as a technical fix for a bureaucratic problem, not as a call to arms for Brexit partisans.

One reason is that Brexit has lost much of its political potency as the U.K. has had to weather a pandemic, war in Europe, and a cost-of-living crisis. Lawmakers who used to decry the EU as an undemocratic behemoth know that their voters are more interested in gas bills and economic growth.

“Brexit is increasingly coming to be seen as an economic and not a cultural issue,” Anand Menon, a professor of European politics at King’s College London, told me.

That clears the way for better bilateral relations. Mr. Sunak is a pragmatist who wants to move on from Brexit. It won’t be easy. The U.K. and the EU still need to negotiate on issues like data sharing and fishing quotas. But there seems to be a new level of trust to build on.