“A historic document”: Details of the Polish–British defence treaty

On Wednesday, 27th May, in London, the Prime Ministers of Poland and the United Kingdom signed a treaty on partnership in security and defence.

A historic treaty

The place chosen for the signing was no coincidence. It was Uxbridge in London, where, during the Second World War, the command of No. 11 Group RAF was located, the unit that issued orders to the Polish pilots of No. 303 Squadron as they fought against the air forces of the Third Reich.  “This is a historic document in a historic place, and it will make our future safer,” Prime Minister Donald Tusk said shortly after the treaty was signed.

According to the head of the Polish government, the document is intended to strengthen cooperation between the two countries in the field of conventional defence. Protection of cyberspace in both Poland and the United Kingdom is also to be enhanced. As the Prime Minister stressed, the treaty is intended to reinforce NATO, not to compete with transatlantic cooperation. Before departing for London, Prime Minister Tusk explained it as follows: “Since NATO has Article 5, why do we need treaties with France or the United Kingdom? Thanks to them, in the event of a threat, we will be able to count on swift bilateral responses before a decision is taken by all 32 NATO members,” he said.

After the signing of the treaty in London, Prime Minister Tusk continued this line of argument: “We are doing this within NATO in order to strengthen NATO. We want to be faster in our response. The political essence of this document is to strengthen European solidarity, solidarity within the Alliance, and transatlantic solidarity.” 

UK Prime Minister Keir Starmer, for his part, stated that the treaty opens up opportunities for new joint investments and sends a signal to the world about the strengthening of Polish–British relations.

New SAM systems?

The agreement provides for cooperation between the two countries in the fields of defence industries, migration policy and the coordination of support for Ukraine.

According to our information, Polish–British cooperation is to include, among other things, the development of new air-defence effectors and the strengthening of air and missile defence systems. The two countries would also jointly produce next-generation medium-range anti-aircraft missiles.  In addition, the land forces of Poland and the United Kingdom are expected to conduct joint exercises aimed at increasing interoperability in counter-drone operations, electronic warfare and engineering support. Warsaw and London are also set to accelerate cooperation in countering destabilising activities by hostile states, including cyberattacks and disinformation campaigns.

The treaty on partnership in security and defence with the United Kingdom is another document of this kind concluded by the Polish government in recent months. On 9 May 2025, in Nancy, Prime Minister Donald Tusk and French President Emmanuel Macron signed the Treaty on Enhanced Polish-French Cooperation and Friendship.