UK’s growing post-Brexit international leadership

One of the biggest claims made by some key Brexiteers in the 2016 referendum campaign was that the UK would become a global buccaneer if it left the EU. However, multiple, subsequent UK governments were criticized for their lack of international engagement.
Fast forward almost a decade to 2025, however, and there are some signs that the UK is waking up from this diplomatic downtime.
On Thursday and Friday, for instance, the UK government co-hosted with the International Energy Agency a big international conference on energy security — ahead of the important COP30 in Brazil. Especially since Russia’s invasion of Ukraine, this topic has moved up the global agenda as countries seek to respond to protect themselves from potential future shocks.
It is no coincidence that the IEA chose to host the big event in London. Prime Minister Keir Starmer’s government is one of the most politically stable in Europe right now. Whereas UK governments between 2016 and 2024 had either small legislative majorities, or were constrained by the COVID pandemic, last year’s election saw Labour win the largest margin in the House of Commons for more than a quarter of a century.
This means Starmer can be confident of his party remaining in office for a full parliamentary five-year term till 2029, unless he or a successor decide to call an early ballot. In turn, this domestic stability has created a post-Brexit political window of opportunity for Starmer and his ministers to spend much time on foreign policy in their first year in office.
Starmer has also recommitted for the UK to become a “clean energy superpower.” He and his government’s ministers used the IEA summit to advance this vision, including UK plans to accelerate a new era of clean electricity by 2030.
Dozens of attendees from government and the private sector, from Africa, the Americas, Europe, the Middle East, and the Asia-Pacific region, joined the big event. European Commission President Ursula von der Leyen was one of the biggest name politicians of the approximately 60 governments at the event.
The IEA event builds from the UK Investment Summit last autumn, which the government claims saw more than £60 billion ($79 billion) in new investment announced by business, about half in clean energy. It also follows last year’s launch of the new Great British Energy — an investment body and publicly owned energy generation company which aims to ensure a massive expansion in clean energy.
Since the Starmer government came to power last July, it also has confirmed funding to launch the UK’s first Carbon Capture, Utilisation and Storage sites. In a more than £20 billion commitment, two new CCUS-enabled hydrogen projects will help remove more than 8.5 million tonnes of carbon emissions each year, which is the equivalent of taking about 4 million cars off the road. 

Prime Minister Keir Starmer’s government is one of the most politically stable in Europe right now.

Andrew Hammond

Moreover, the government overturned a nine-year ban on onshore wind power construction under the last several Conservative governments. This was followed by one the most successful renewable auction rounds in UK history.
Given the emphasis that the UK government is putting on the energy agenda, it is no surprise that this issue will be one of the key focuses of the UK’s new, anticipated 2025 Brexit reset deal with the EU, alongside defense and fisheries. One of the energy topics under discussion between Starmer and von der Leyen is closer alignment on electricity trading, plus greater cooperation between the EU and UK on carbon emissions trading schemes. Moreover, von der Leyen urged Starmer to build a joined-up regulatory framework for investors backing renewable energy infrastructure in the North Sea in offshore wind, marine energy, hydrogen, as well as carbon capture and storage.
Yet, as much as Starmer will have many welcome friends at the summit, there may also be more challenging ones, too. A key goal of the summit was to try to build a greater consensus on a holistic approach to energy security, ensuring governments have the tools they need for the challenges and opportunities confronting them.
US Acting Assistant Secretary of Energy Tommy Joyce attended on behalf of the US. Joyce, like Trump, is an avowed opponent of global climate diplomacy. Joyce has asserted that the US “will not sacrifice our economy or our security for global agreements for a so-called net-zero future, nor do we encourage any other nation to make that sacrifice either.”
This critique builds from that of US Energy Secretary Chris Wright, specifically of the UK. He has slammed UK adherence to net-zero policy, in particular, for resulting in what he claims to be “higher prices and fewer jobs for UK citizens, higher global greenhouse gas emissions, and all of this is a climate policy?”
The clash between the Trump team and that of Starmer could not be much starker on this issue. The UK government’s alternative pathway to energy security is through commitment to net zero, investment in renewables, as well as phasing out fossil fuels.
As on the Ukraine agenda, where the Trump team is publicly showing much sympathy for Moscow rather than Ukraine, it is the White House that poses one of the major headaches to the UK’s advancement of its global energy security vision shared by much of the rest of the world, too. This may threaten any big climate agreement breakthrough being reached at COP30 in Brazil.
So many big battles may lie ahead with this important agenda. Yet, co-hosting the IEA event is another sign of a ramp-up in the UK’s growing post-Brexit international leadership in a geopolitical and geo-economic landscape in flux.

• Andrew Hammond is an associate at LSE IDEAS at the London School of Economics.