Description
On 17th July 2025, Chancellor Friedrich Merz and Prime Minister Keir Starmer signed a landmark treaty on friendship and cooperation between the United Kingdom and Germany. Immediately dubbed the “Kensington Treaty”, the aim of the new agreement was to strengthen bilateral relations between two of Europe’s largest economies, one an EU Member State, the other now an outsider. The two sides expressed their ‘desire to join forces for a prosperous, secure and sustainable future for their citizens and their open, democratic societies in the face of fundamental changes in the geopolitical environment’. The Kensington Treaty covers a wide array of policy areas, including ‘diplomacy, security and development’, ‘defence cooperation’, ‘internal security, justice and migration’ and ‘economic growth, resilience and competitiveness’. That the UK should seek a bilateral arrangement with the EU’s largest Member State was unsurprising – bilateralism was a hallmark of the UK’s engagement with other countries before Brexit and they are arguably even more crucial for third countries than for EU insiders. Yet how do we account for the decision of Germany, one of the EU’s most committed members, to engage is such a comprehensive treaty with the UK? Drawing on in-depth analysis of documentary sources as well as off-the-record interviews with key decision-makers in both countries, the article seeks to understand the motivations for the treaty, how the bilateral and multilateral relationships can co-exist for each side, and the likely implications for new patterns of external differentiated integration as the UK pursues its wider reset with the EU-27.
