British Prime Minister Keir Starmer and Polish Prime Minister Donald Tusk sign the Northolt Treaty, a defence and security agreement intended to deepen cooperation between the UK and Poland. The pact is aimed at improving coordination and joint capabilities, including air defence cooperation and broader security efforts. Sources also describe provisions related to countering Russian hybrid threats and strengthening practical coordination in areas such as cyber defence. Both leaders present the deal against a backdrop of heightened concern over Russia’s actions and potential destabilization in Europe. The reporting links the timing of the treaty to recent incidents involving drones and missiles affecting NATO’s eastern flank, as well as wider warnings that Russia is increasing mobilization. In addition to military and security cooperation, the treaty also includes a joint action plan on irregular migration. The agreements reinforce ties between two NATO member states as both governments seek to respond jointly to perceived security challenges.