UK-Germany Kensington Treaty takes effect as Burnham and Merz meet in Berlin

UK Prime Minister Andy Burnham met German Chancellor Friedrich Merz in Berlin on 8 October as the Kensington Treaty entered into force, giving the two governments a framework for closer cooperation on security, economic ties and other shared priorities. The UK government also announced a partnership to counter cyberattacks, sabotage and other hybrid threats. The announcements set out work the countries intend to pursue; their practical effects have yet to be demonstrated.

Burnham’s visit followed previously reported plans for security talks with Merz in Berlin. What changed on Thursday was the treaty’s entry into force and the announcement of a counter-hybrid-threat partnership. Deutsche Welle reported that Merz received Burnham with military honours and that the leaders held one-on-one talks during the visit.

What the Kensington Treaty commits the UK and Germany to do

The UK and German governments signed the treaty in London on 17 July 2025. Then Prime Minister Keir Starmer signed for the UK and Merz for Germany. Its text says it enters into force when the countries exchange their instruments of ratification; the UK government said it was formally ratified on 8 October. The signing and Thursday’s entry into force are separate steps.

On foreign and security policy, the treaty provides for consultations and closer cooperation on intelligence and national security capabilities. Article 4 calls on the governments to strengthen their ability to detect, deter, disrupt and respond to hybrid threats. It names sabotage, malicious cyber activity and foreign information manipulation among those threats. These provisions establish areas for joint work, rather than reporting an operation already carried out under the treaty.

Its scope extends beyond security. The governments commit to work together on growth, jobs, digital transition, innovation and investment, including links between businesses and industries. They also agree to pursue climate diplomacy and support developing countries with decarbonisation and adaptation to climate effects. Those commitments identify fields for cooperation; the reviewed accounts do not establish their effect on residents or businesses.

How the new partnership would address cyberattacks and sabotage

In its announcement during Burnham’s visit, the UK government said the separate counter-hybrid-threat partnership would involve sharing information and coordinating action to monitor, deter and disrupt hostile activity. It identified cyberattacks, sabotage and threats to critical infrastructure as targets for that work. The announcement describes an intended approach, without providing results from joint activity under the partnership.

The UK government singled out Russia in its account of hybrid threats. That is the government’s assessment in the announcement, which does not independently establish the source or scale of particular incidents. Burnham said attacks on infrastructure, businesses and democracies can reach homes and workplaces, and said Britain and Germany were joining forces to find, expose and disrupt such activity.

Deutsche Welle reported that Merz called the treaty’s launch a historic day and highlighted opportunities for students and young people. Burnham said it would improve European security, help both economies grow and raise living standards. Those are the leaders’ expectations. Neither the treaty’s entry into force nor their remarks demonstrate that those outcomes have occurred.

What happens after the Berlin meeting

The treaty provides for consultations led by the heads of government every two years, alongside an implementation plan covering projects for each following two-year period. That process offers a way to assess what the governments actually do under the agreement. The text also says either country may terminate it by written notice, with termination taking effect six months later unless they agree another date.

Some ambitions will depend on later decisions and delivery. The treaty says the countries will seek to facilitate direct long-distance passenger rail services between them; it does not establish that a service has begun. The UK government also said Burnham and Merz would convene a regional growth forum with British and German chief executives focused on investment and industrial partnerships. Its announcement does not report investment outcomes.

The UK government said the leaders would discuss support for Ukraine, instability in the Middle East and disruption to trade routes including the Strait of Hormuz. It did not report decisions on those subjects. For now, the confirmed development is the treaty taking effect and the announced security partnership; the extent of subsequent cooperation and its effects remain open to assessment.