Abstract. The article provides a comprehensive analysis of the evolution of NATO policy within the context of the russian-Ukrainian war. The North Atlantic Alliance consistently demonstrates its commitment as a reliable guarantor of peace, security, and stability for its member countries. The foundation of NATO’s accomplishments lies in its dependable and effective institutional structure, well-regulated political consultation mechanisms geared towards consensus-building, and the aspiration to constantly maintain and improve the balance of transatlantic interests. The russian invasion of Ukraine has prompted a critical reassessment of NATO’s role and its development prospects, primarily regarding the imperative of strengthening the Alliance’s defensive potential, the expansion of its operational scope, and the refinement of its security missions. The new Strategic Concept outlined NATO’s priorities, core objectives, and approaches. It also identified the main threats to Euro-Atlantic security and proposed countermeasures for the next decade. The Alliance reacted to the kremlin’s aggressive intentions by activating its defence plans and deploying additional military formations on NATO’s eastern flank, backed by significant air and naval potential. Moreover, the Alliance enhances the reliability of nuclear forces, strengthens the operational capabilities of conventional armed forces and anti-missile defence assets, and reinforces the resilience of member countries for collective defence. An analysis of Ukraine’s relations with NATO amidst the large-scale russian aggression underscores that the heroic resistance of the Ukrainian people could facilitate a quick accession of Ukraine to the Alliance following the end of the war. An invitation to Ukraine at the 2023 Vilnius Summit opens prospects for establishing long-term sustainable peace in Europe. Keywords: NATO, russian aggression, Strategic Concept, NATO expansion, Euro-Atlantic integration of Ukraine.