LONDON — Keir Starmer and Friedrich Merz have signed a wide-ranging friendship treaty pledging closer co-operation on security — including a promise to come to one another’s aid in the event of an armed attack. 

Merz traveled to London for the first time as German chancellor to sign the pact, which spells out a shared approach to foreign policy and which names Russian aggression as the “most significant and direct threat” to the two countries’ security. 

The document commits the two European state to deeper co-operation with France too — formalizing the so-called “triangle alliance” for the first time.

Starmer’s spokesman said recent visits by Merz and Emmanuel Macron reflected the efforts by the U.K. prime minister to reset relations across Europe, including closer ties with both France and Germany.

As part of the accord, Britain and Germany will enter into a mutual assistance arrangement for the first time, declaring they are “convinced that there is no strategic threat to one which would not be a strategic threat to the other.”

While both sides are keen to stress that NATO remains their primary security alliance, the move underlines a shared determination between Merz and Starmer to strengthen Europe’s defenses. 

Defense trade barriers between the U.K. and Germany will also be eased under the treaty, which lays the groundwork for tackling hybrid threats such as attacks on infrastructure and malicious cyber activity.

Alongside the agreement signed Thursday, the two sides announced they would launch joint export campaigns and work together on a new long-range missile system. 

Frequent travelers to Germany from the U.K. will meanwhile gain access to e-gates in a pilot program ahead of a wider rollout which will take place after the German authorities complete technical changes.

With both leaders under pressure to reduce migration at home, Starmer was keen to highlight commitments already given by Germany to ramp up the prosecution of smuggling gangs.

The treaty refers to “the joint fight against organised cross-border crime involving migrant smuggling,” alongside chapters on economic growth, exchanges between citizens and climate.

Ahead of their meeting, Starmer hailed the treaty as ”the first of its kind” which “will bring the U.K. and Germany closer than ever.”