The nuclear pact recently signed by Emmanuel Macron and Keir Starmer reflects how an emerging post-liberal Europe is taking the form of a defence community. Britain can help shape the continent’s new security order, so long as it banishes the Brexit mindset.
Many state visits are empty, symbolic acts that have little to no policy content or lasting significance. But every now and then, such a visit changes the shape of international relations. Could French president Emmanuel Macron’s recently concluded trip to London be one of them?
Macron’s three-day trip, the first state visit to Britain by a European Union head of state since Brexit in 2020, had plenty of pomp and pageantry. But it also focused on policy and politics, which reflects a profound shift in the UK’s circumstances since leaving the EU.
During the upheaval of the Brexit psychodrama, there was little interest in constructive exchange, and the UK’s relationship with Europe remained defined by its lurching departure from the bloc. But nearly a decade on, US president Donald Trump is back in the White House and has launched a trade war on the world. Vladimir Putin has shredded the European security order. And Chinese president Xi Jinping has resorted to threats of economic coercion—a striking reversal from the “golden era” of UK-China relations proclaimed in 2015.
Even more dramatic, perhaps, are the changes in the EU. The big policy initiatives launched during Macron’s UK visit reflect the forces that are turning the bloc on its head.
First, the EU is moving from a peace project to a war union. For most of its existence, the EU sought peace through economic integration. But Putin’s invasion of Ukraine in 2022 reoriented the bloc toward security—a goal that has taken on greater urgency since Trump cast doubt on America’s commitment to collective security on the continent.
There is broad support for this new orientation. According to a recent opinion poll conducted by the European Council on Foreign Relations, many Europeans favour increased defence spending, conscription and the development of a European or national nuclear deterrent.
Against this backdrop, Macron and British prime minister Keir Starmer took a bold first step toward establishing an independent nuclear deterrent with the Northwood Declaration, in which they agreed that “there is no extreme threat to Europe that would not prompt a response by our two nations”.
A second major change is the development of “securonomics”. The EU economy is under pressure from Trump’s tariffs and China’s export restrictions on magnets and critical minerals. EU policymakers now talk of de-risking, diversifying and deepening the single market, rather than pursuing free-trade agreements. While the UK has made it clear that it will not rejoin the single market or the customs union, the question is whether it can persuade the EU that it can be counted on to help the bloc achieve its new trade goals, or whether it will be given unfriendly treatment because it is seen as posing a risk to those objectives.
Domestic politics in Europe has also undergone a rapid transformation. It has been fascinating to watch Macron—once a poster boy for liberal universalism—reinvent himself as a champion of secure borders and protectionism, while taking a tougher stance on crime. This volte-face has seen mainstream European politicians shift focus toward defending national sovereignty—from Russia, China, Trump and migration—while they try to contain populist parties such as France’s National Rally (RN) and Germany’s Alternative for Germany (AfD). That is the backdrop for the groundbreaking deal that Starmer and Macron signed on migration returns.
Starmer’s approach to Europe is a marked improvement from that of former Conservative prime ministers Boris Johnson (who compared the EU to Napoleon and Hitler) and Liz Truss (who questioned whether Macron was a friend or a foe). Starmer has proved himself, particularly with his deft diplomacy on Ukraine, to be a reliable partner and stakeholder, regaining the trust of EU institutions and member states. One senior German policymaker told me how impressed he was by the UK filling the leadership vacuum created by Trump’s disregard for Ukraine.
In other words, the UK is widely seen in Europe as being “part of the team” again. The EU-UK summit in May provided a clear framework for deepening the relationship, not least through a Security and Defence Partnership that paves the way for British participation in European defence programmes.
But the UK government has remained far too cautious in other areas. Most notably, Starmer has been careful not to cross the Labour Party’s self-imposed red lines: no freedom of movement, no customs union and no single market. Future historians may well wonder why Starmer did not aim higher.
The changing international environment offers Starmer a clear opportunity to redraw Europe’s political map, which would establish him as one of Britain’s most consequential leaders. But to do so, Starmer must convince British voters that today’s Europe is a different creature from the one they imagine: a defence community that is more focused on safeguarding the continent than on transcending the nation state. And he must explain how the UK can help build this new European security order, so long as it banishes the Brexit mindset.
As a post-liberal Europe emerges, Britain must stop clinging to the past and seize the chance to shape the continent’s future in a way that advances its interests. That requires acknowledging that both the EU and the UK have entered a new era.
About the author:
Mark Leonard is co-founder and director of the European Council on Foreign Relations, the first pan-European think–tank.