Britain long played a special role within the European Union, as a nuclear power and permanent United Nations Security Council member that had Washington’s ear. It was also a budget hawk that insisted on keeping the bloc’s spending in check. Some EU officials worried that the U.K.’s exit from the bloc would weaken a union that had been under pressure since Britons voted in 2016 to depart. That vote confronted the EU with the risk of disintegration and strengthened the hand of euroskeptic movements from Italy to Hungary.

Instead, as the U.K. prepares to leave the EU’s economic orbit Jan. 1, the EU has regained confidence, helped partly by a revived Franco-German partnership and encouraged by the anticipated arrival of the Biden administration in Washington. Meanwhile, Paris, now the bloc’s dominant foreign-policy actor, is driving debate on everything from relations with Washington and Moscow to expanding the EU’s military capabilities.

Last week’s Brexit agreement is due to be approved by EU governments on Tuesday and by the British parliament on Wednesday to allow it to come into force provisionally on Friday. The European Parliament will consider the 1,246-page deal, published in full on Saturday for the first time, in the new year. Top EU lawmakers from the bloc’s biggest parties have already welcomed the deal. During several years of acrimonious Brexit talks, many feared that a failure of the EU and the U.K. to reach a deal on their future relations could poison bilateral ties, even threatening the U.K.’s still sizable contributions to European security—from the Baltic states to the antiterrorism campaign in Africa’s Sahel.

Confidence GrowsTrust in the EU has recovered since the 2016Brexit referendum.Trust in government institutions source: Standard Eurobarometer survey of face-to-face and phone interviews of 27 member states %EuropeanUnionNationalparliamentNationalgovernment2005’10’15’202030405060

Britain’s sway in the continent, long a useful channel for Washington to influence EU plans on trade, tax and foreign-policy priorities, is much diminished. However, Thursday’s agreement between Britain and the EU on future economic, trade and security ties should prevent a permanent rift between America’s European allies.

Britain’s repeated political crises since the referendum have, opinion polls show, lifted support elsewhere for EU membership. Many anti-EU populist champions now call for overhauling, rather than quitting, the bloc.

This year, the EU has agreed to a huge recovery fund to help the bloc emerge from its coronavirus slump—an agreement unthinkable a few years ago. With a Brexit deal now pocketed, some officials believe the EU has turned a corner.

“We showed that if we are really under pressure, we get things done,” Michael Clauss, Germany’s ambassador to the EU, said in December. “So we did rise to the challenges and that’s why, also psychologically, we all feel that we are in a stronger position now.”

Central to the eurozone’s revival is the French-German partnership, which has gained strength with the exit of the only EU member state country that was equal in economic and strategic terms.

Just a year ago, France and Germany appeared at loggerheads on many of Europe’s biggest challenges.