The 1972 ABM Treaty between the USSR and the USA allowed for the deployment of a limited strategic missile defense system, but established a strict ban on the deployment of anti-missile systems outside their national territory. The agreement was the first turn in the U.S. policy in this area, determining the direction and content of missile defense development programs for many years to come. Once every ten years, the United States revised its policy, for instance, R. Reagan's intention in 1983 to build a large-scale space-based missile defense system was seen as an attempt to move away from the concept of mutual nuclear deterrence, enshrined in the ABM Treaty. However, only after its withdrawal from the ABM Treaty in 2002, the United States set a course for the deployment of a missile defense system in Europe, as stated, to protect the region from nuclear missile threats from "rogue states". At the present stage, the growing degradation of relations between Russia and Western countries, especially against the backdrop of hostilities in Ukraine, has led NATO states to put forward new approaches to the integration of missile defense and air defense systems, providing for the functional interface of information management systems and strike components for the successful interception of different classes of targets. The experience of providing Ukraine with integrated defense and its functioning on the basis of modern Western air defense systems will allow the U.S. / NATO to evaluate the effectiveness of the chosen approach and apply the knowledge gained to improve Europe's "anti-missile umbrella". The article proposes the author's periodization of American policy in the field of missile defense, as well as considers each of the identified stages with special emphasis on the last one, which is directly related to the current political situation.
