ObjectivesThe aim of this article is to analyse the determinants of changes in the foreign and security policy of the Republic of Finland and to answer the question of how this country's accession to NATO influenced the balance of power and the security environment in Northern Europe. The results of these analyses will allow us to understand how small states can shape the security environment at both the micro, meso, and macro scale.MethodsDue to Finland's geographical location and its experience in relations with Russia (later the USSR and again with Russia), the article uses a historical and polemological approach. The methodology was supplemented with systemic, quantitative and comparative research.ResultsFinland's accession to the North Atlantic Treaty Organization finally ended its long-standing policy of military non-alignment. Not only the European, but the global security map has changed. There are no longer democratic countries on the map of Europe that border directly on Russia and do not belong to Western military structures. From the Alliance's point of view, Finland's accession is an added value, and this country's greatest advantage is its knowledge and experience in dealing with Russia.ConclusionsIn today's security environment, there is no longer room for either neutrality or military non-engagement. Future research on this issue should approach it in a holistic way, treating the security environment as the sum of military and digital security. Although these two aspects are intertwined, it should not be forgotten that activities in each of them can take place independently.