After a geopolitical phase of peace and international cooperation, the Arctic is witnessing renewed military tensions, particularly between Russia, NATO, and European Union (EU) member countries. The multilateral governance that has so far governed the fate of the Arctic is being challenged by the confrontation between Russia and the West. In addition, climate warming opens up new trade routes. It provides access to immense deposits of raw materials, accelerating competition among actors partly by including external players such as China. To assess the future trajectory of European defense governance on the northern flank, it is necessary to view the Arctic and Baltic as a single region in light of common critical factors.