The purpose of this article is to analyze the influence of Finland on regional policy of NATO and the Russo-Ukrainian war. The article explores political, economic and military aspects of Finland and Ukraine in the light of the Russian aggression while considering their relationships and foreign policy goals on a regional level. The author draws attention to various aspects of Helsinki domestic and foreign policy that is directed to set a balance in the region and, at the same time, to support Kyiv militarily and economically in confrontation with Moscow. Finland’s active policy of promoting stability can be described as a two-track policy, whereby EU membership and intensified military cooperation with Western partners provide a basis for the maintenance and development of relations with Russia. The author focused on energy resources and its importance for Finland that has a long history of energy trade with Russia. The trade is practically one-directional, as Finland lacks domestic fossil fuel reserves in comparison with its substantial demand for energy, whereas Russia has significant export volumes. Along with the above-mentioned issues, the author is observing aggressive Russian military activities in the Baltic Sea region. Despite peaceful relationships with Finland, Moscow does not mind to remind neighboring countries who calls the tune in the region. Pursuing this purpose, Russia increases military activity in the Baltic Sea region with relatively frequent airspace and territorial water violations. As a result, there is a risk that collisions or provocations might lead to a rapid and uncontrolled escalation. So, Finland finds its important to keep open channels for political dialogue and to seek ways to re-activate existing confidence-building measures. Finland-NATO relationships are taken into consideration as well. The author described the process of Finland’s accession to the alliance. After almost 30 years of close partnership with NATO, Finland joined the Alliance on April 4, 2023. Its partnership with NATO was historically based on its policy of military non-alignment, which changed following Russia’s full-scale invasion of Ukraine in February 2022. Following Russia’s aggression, Ukraine has requested materiel assistance from the EU and NATO member countries. To date, Finland has donated 23 defence materiel packages to Ukraine. The combined value of all defence materiel packages submitted so far is now over EUR 2 billion.