An analysis of the military and political preconditions for the current transformation of the North Atlantic Treaty Organization (NATO) is presented. The deterioration of relations between Russia and NATO member states, which accelerated with the outbreak of hostilities in Ukraine accompanied by massive supplies of Western weapons systems to Kiev, launched the reconfiguring of the entire system of military and political decision-making and defense planning process in NATO. The alliance is returning to its original mission – countering the “Russian threat” (formerly Soviet), despite the fact that NATO is not declaratively a party to the armed conflict in Ukraine. NATO’s reaction and actions in connection with the Ukrainian crisis and the start of the Special Military Operation (SMO), including the plans of the alliance’s leadership for the future, are analyzed. The simplification of a number of procedures and requirements in the defense planning system of the organization in the short and medium term are noted. The full cycle of NATO defense planning is examined in detail and schematically presented, and a forecast of its further evolution is given.