Polish Prime Minister Donald Tusk and British Prime Minister Keir Starmer signed a security and defence partnership agreement on 27 May at RAF Northolt military base near London.
According to the Office of the Polish Prime Minister, the new document elevates bilateral relations between Warsaw and London to a qualitatively higher level. The primary objective of the agreement is stated to be the strengthening of deterrence against a potential aggressor — with Russia explicitly named in the text.
The treaty defines Russia as “the principal long-term challenge to Euro-Atlantic security.” The parties commit to jointly countering Russian aggression and interference, coordinating sanctions policy, continuing military support for Ukraine, and participating in its post-war reconstruction.
Significance is attached to the mutual defence guarantee. The document emphasises that in the event of an armed attack on either country, the other will render assistance, including by military means, in accordance with Article 5 of the North Atlantic Treaty.
Poland and the United Kingdom also intend to strengthen cooperation on NATO’s eastern flank and to coordinate their forces and actions with other allies.
The signing of the treaty took place against the backdrop of Russia’s ongoing war against Ukraine and growing concern among European capitals regarding Moscow’s long-term intentions. The agreement is expected to become an important element of bilateral cooperation outside EU structures, particularly following the United Kingdom’s departure from the European Union.