On July 18, 2025, Prime Minister Keir Starmer of Britain and Chancellor Friedrich Merz of Germany formalized a comprehensive treaty focused on mutual defense and economic collaboration. In concert with this, Starmer and President Emmanuel Macron of France have agreed to coordinate their nuclear strategies. This comes on the heels of a symbolic trip the three leaders took to Ukraine in May to signal their unified support against Russian aggression, and further discussions are set for Macron's visit to Berlin next week.

Collectively termed the "triangle alliance," Britain, France, and Germany are also mobilizing efforts to aid Ukraine as American military support appears to decline. Their coalition is expected to establish a formal headquarters in Paris for this initiative, alongside ongoing planning for a possible European-led peacekeeping force in Ukraine. Concurrently, the European Union has announced its most recent sanctions package against Russia.

While these three nations maintain ties through existing alliances like NATO and the G7, they are keen on developing a more agile framework that can adapt quickly to geopolitical shifts. Officials assert that these new structures will complement rather than replace existing partnerships, although they are cautious of the complexities associated with collaborating within larger organizations that encompass numerous member states with varying priorities.