This study focuses on the Treaty of Strengthened Cooperation and Friendship between France and Poland, concluded in Nancy on 9 May 2025. To identify its role for French and Polish foreign policy and the Euro-Atlantic security architecture, the article explores the main provisions of the agreement and determines whether they correspond with the strategic interests of Paris and Warsaw. The treaty is examined within the framework of the two countries’ foreign policy priorities in recent decades, as well as bilateral relations. The article analyzes the factors that prompted the parties to conclude the treaty at this stage and its possible implications for Polish-French dialogue and European processes as a whole. It reveals that the reasons in favor of the treaty include both national context in both cases (the intensification of French interest in Eastern Europe and the coming to power of a «pro-European» government in Poland) and more general processes (the conflict in Ukraine and the contradictions between the new US administration and its European allies). At the same time, despite the agreement’s overarching nature and its references to various areas of cooperation, the main discussions in France and Poland revolved around the issue of mutual military assistance, the possibilities of military-technical cooperation, as well as nuclear deterrence, which is imprecise under the agreement.