The Germany-UK treaty: a historic agreement for difficult times

During Chancellor Friedrich Merz’s (CDU) visit to London on 17 July, a British-German Friendship and Bilateral Cooperation Treaty (Kensington Treaty) was signed. It provides for cooperation in many areas: from foreign policy, the economy and innovation, to the energy transition and agriculture. Both sides devoted most attention to enhancing cooperation in the field of security, including internal security (migration) and defence. The Treaty emphasised the importance of NATO and referred to the commitments under Article 5 of the Washington Treaty, reaffirming them, while also including an additional defence clause. The United Kingdom and Germany have committed themselves to providing mutual assistance, including by military means, in the event that either country comes under armed attack. They stated that there is no strategic threat to one party that would not simultaneously pose a threat to the other. Both countries will maintain a close dialogue on defence issues of shared interest, including nuclear matters. They defined Russian aggression on the European continent as the most significant and direct threat to their security. In a separate document, the United Kingdom and Germany announced the implementation of 17 projects, which will be evaluated every two years during bilateral intergovernmental consultations (see Appendix).

For Germany, the new treaty confirms its will to enhance cooperation with its most important European ally outside the EU. It is also meant to seal the joint action by both countries in light of the prospect of a reduced US engagement in Europe. From the United Kingdom’s perspective, the agreement with Germany is intended to shape post-Brexit cooperation in security and the economy with a strategic partner on the continent. London and Berlin view the treaty as a complement to their enhanced cooperation with Paris and as a signal of the greater use of the E3 format (United Kingdom, France, Germany) in European security (see ‘France and the United Kingdom: the beginning of bilateral coordination of nuclear deterrence’).

Commentary

• The treaty is the first such comprehensive agreement concluded between Germany and the United Kingdom since the Second World War. Work on it was already underway under the government of Olaf Scholz (SPD). In October 2024, the two sides signed a defence agreement to extend military cooperation and ties between their defence industries. These documents form part of Germany’s policy of fostering as close a relationship as possible with the UK after Brexit. Its implementation is supported by concerns over the future of the US military presence in Europe, the Russian threat, and the Keir Starmer government's openness to cooperation with the EU.
• The new treaty completes the ‘triangle’ of similar agreements among Europe’s economically and militarily strongest states – the United Kingdom, France and Germany – within the E3 format. The intention is for this triangle to form the core of coordinated efforts for European security, with the possibility of it being expanded to include other actors, such as Italy and Poland. At present, the focus is on ensuring stable support for Kyiv (the UK and France coordinate the so-called Coalition of the Willing, while the UK and Germany are involved in the Ramstein group), shaping relations with the United States, and stabilising the situation in the Middle East. The United Kingdom, France and Germany view their security as permanently interconnected, which carries certain risks – namely, the emergence of a two-tier security structure in Europe (with a western zone of enhanced guarantees) and the E3 format being dominated by the US–Europe dialogue.
• Germany and the UK have identified their engagement in NATO and the fulfilment of their allied obligations as the foundation of their security, as well as their commitment to closer NATO-EU cooperation. However, the mutual defence declaration does not entail significantly enhanced cooperation between the German and British armed forces. There are no plans to create permanent joint formations (such as the Franco-German Brigade) or combined forces (such as the UK–France Combined Joint Force). Instead, the two sides agreed to expand existing exchange programmes (officers from one country will serve in the other country’s units), as well as to conduct joint training and staff courses. From the perspective of NATO’s frontline states, it is significant that both countries plan to develop multi-domain cooperation focused on participation in high-intensity collective defence operations, with particular attention paid to the northern and eastern flanks. In the context of protecting critical infrastructure and maritime communication lines, last year’s defence ministries agreement announced the occasional deployment of German P-8A aircraft in Scotland (once they enter service), designed for submarine detection and anti-submarine warfare.

• The already well-developed cooperation between the UK and German defence industries is set to be further strengthened. However, in recent years, it has been asymmetrical – primarily based on the export, production, and joint development of German systems in the UK. Enhanced cooperation focuses largely on the maintenance and development of the weapons and military equipment used by both countries (e.g. Boxer armoured vehicles, RCH 155 self-propelled howitzers, and new torpedoes for maritime patrol aircraft), as well as on investments in emerging technologies such as artificial intelligence in weapons systems, counter-drone defences, and cybersecurity. The announced harmonisation of arms export laws (with the UK joining the relevant 2019 treaty between Germany and France – Spain having already joined) may lead to a significant increase in arms exports and improve the profitability of European defence projects. Differences in export legislation remain one of the greatest obstacles to exporting multinational weapons systems, particularly to non-European markets. Crucially, in the context of deterring Russia, the UK and Germany will continue to work on long-range cruise missiles under the European Long Range Strike Approach.
• The content of the treaty and the agreed projects indicate a desire to intensify cooperation in areas such as infrastructure, the economy and new technologies. For the United Kingdom, Germany is its second-largest trading partner, while for Germany, the UK ranks ninth. From Britain’s perspective, the treaty offers an opportunity to improve economic relations with Germany post-Brexit. In 2016, the UK was Germany’s third-largest trading partner. Over the next decade, both countries will work on developing a hydrogen corridor and establishing a direct rail link between London and Berlin. They also announced plans to establish a strategic partnership in the fields of space and semiconductors.

Appendix. Selected initiatives from joint British-German projects listed in the annexe to the Friendship and Bilateral Cooperation Treaty

1. Ukraine recovery & reconstruction

• Joint actions to support Ukraine’s reform, reconstruction and resilience
• Coordination of humanitarian, development and peace assistance

2. Defence cooperation (implementation of the Trinity House Defence Agreement)

• Advancing work to develop a new Deep Precision Strike capability (2,000 km+) within the European Long Range Strike Approach (ELSA)
• Cooperation in uncrewed aerial systems and air force interoperability
• Land strategic partnership (including RCH 155 artillery, Boxer wheeled transport vehicles)
• Undersea co-operation, including training of German crews on UK P-8A Maritime Patrol Aircraft and joint procurement of new Sting Ray torpedoes

3. Strengthening defence industrial and export cooperation

• Joint tenders and export campaigns
• Development of cooperation within the UK-Germany Defence Industry Forum

4. Joint action plan on irregular migration

• Increasing cooperation against migrant smuggling by strengthening law enforcement and judicial cooperation, stepping-up efforts on returns
• Germany adopting legislation to punish the facilitation of irregular migration to the UK
• Improving law enforcement, policy and prosecutorial cooperation against organised crime groups smuggling and trafficking people
• Cooperation under regional formats (Calais Group and Berlin Process)
• Continuing mutual support in managing migration systems and delivering secure borders

5. Strategic science and technology partnership

• Cooperation in quantum, AI and digital technology, semiconductors, space capabilities and sustainable energy solutions

6. North Sea energy infrastructure projects

• Development of energy connections and hydrogen projects

7. Joint task force on a new rail link between UK and Germany
8. E-gates

• Facilitations for UK citizens travelling to Germany

9. School trips and mobility of citizens

• Introducing visa-free school group travel between the UK and Germany
• Appointing a Joint Expert Group on mobility

10. Business cooperation

• Promoting cooperation between German and British companies (including through the Business-Government Forum) and identifying areas of high growth potential

11. Strategic conflict prevention and stabilisation partnership
12. Western Balkans stability and security

• Joint initiatives focusing on the region carried out under the Berlin Process
• Supporting the region’s security and Euro-Atlantic integration

13. Indo-Pacific cooperation

• Strengthening coordination on regional and maritime security
• Joint economic and climate initiatives

14. Biosecurity cooperation

• Exchanging information, increasing resilience against biological weapons and bioterrorism, and improving preparedness to respond to highly pathogenic pathogens
• Joint exercises

15. Strategic sustainable development partnership

• Building alliances to advance the 2030 Agenda
• Holding an annual Development Dialogue, including to support the Global South countries

16. Education, culture, sport

• Increasing the number of school exchanges
• Revitalising cooperation under the UK-German Cultural & Education Commission

17. Public Financial Institutions collaboration

• Deepening market and capital links between British institutions (British Business Bank, National Wealth Fund, British International Investment), and the German state-owned development bank (KfW)

Source: ‘Friendship and Bilateral Cooperation Treaty: The 17 Projects the UK and Germany will deliver together’, 17 July 2025, gov.uk.