UK, Poland to Sign Defense Treaty to Tackle Threats Across Europe

The UK and Poland will sign a new defense and security treaty on May 27, aimed at strengthening cooperation in the face of increasing threats across Europe, the governments of both nations stated.

The deal, set to be signed when Polish Prime Minister Donald Tusk meets with British Prime Minister Keir Starmer in London, will improve border security, tackle organised crime, and deepen defense cooperation with the European Union, a May 26 statement from the British prime minister’s office states.

Tusk and Starmer will discuss what the statement says was a major uptick in hybrid attacks, including “Russian-ordered arson attacks in East London, cargo fires in Birmingham and across Europe, as well as cyber-attacks and espionage.”

“Britain and Poland are already close allies and friends, but the challenges Europe now faces [demand] an even stronger partnership,” Starmer said, according to the statement.

“This treaty is the biggest step forward in our defense and security relationship with Poland in a generation, allowing us to confront modern security threats that may be less visible but no less dangerous, and our collective work together will keep our countries safe for years to come.”

In a Polish government meeting on May 26, Tusk said that the signing of the treaty would be a “historic moment.”

“Both sides emphasize that Russia is a strategic threat, also a long-term one, for Poland, for Great Britain, for NATO, and therefore our cooperation should be focused on securing Poland and other countries against the Russian threat,” Tusk told reporters on May 27.

“History teaches us that Poland must build credible alliances that deter potential aggressors. The goal is to avoid conflict, and the treaty between Poland and Great Britain is precisely that.”

Tusk said that beyond defense, a significant part of the treaty focused on cybersecurity. Poland stated that its role as a hub for military aid to Ukraine has made it a key target for Russian espionage, cyberattacks, and disinformation.

On the defense part of the deal, the British government stated that it would seek to combine expertise and industrial capability to lead the development of complex weapons, including new sophisticated munitions and the co-production of a medium‑range air defense missile.

The move comes at a time when European NATO partners are being pushed to stand on their own feet in terms of defense by U.S. President Donald Trump, who has been critical of the lack of investment by some of the continent’s member states.

Poland signed a similar defense treaty with France in 2025, boosting defense cooperation, and is working on one with Germany, as alliances with European partners take on greater significance for Warsaw.

The Franco-Polish pact includes a mutual assistance clause affirming that the two NATO allies will support one another in the event of an attack. It also outlines commitments to deepen military collaboration and expand partnerships in strategic sectors, including civil nuclear energy.

Although the treaty between Paris and Warsaw stops short of addressing a nuclear umbrella, it does lay the groundwork for deeper integration in civil nuclear technologies, with France aiming to share its expertise as part of a broader energy partnership.

London has likewise signed a treaty with Paris in 2025 and also inked one with Berlin in 2024 and agreed to work on a new strike weapon in 2025.

Reuters contributed to this report.