A thorough refl ection on the COVID-19 phenomenon impact on the process of ensuring international, regional and national security determined the importance to proceed with a research of the diachronic problem aimed at identifying the beginning and the end of the evolution periods of the new type of the COVID-19 coronavirus, to investigate the components of these periods that determine their structure, as well as to consider the level of the internal cohesion between the member and the partner states of the North Atlantic Alliance. The investigation comes to underline the main idea of the subject matter proposed for scientifi c examination, which resides in elucidating the COVID-19 phenomenon periods, aimed at coherent and successive handling by the North Atlantic Alliance and its partner states of the COVID-19 repercussions on the defence and security area by means of ensuring sustainable institutional political and military cooperation and providing necessary resources at each stage to overcome COVID-19 effectively, thus strengthening the national defence and security systems of the partner states, including the Republic of Moldova.