The text starts by briefly exploring the present strategic situation on NATO’s Eastern rim. In a situation clearly dominated by sharply increased Russian aggressiveness, and by the fact that Russia has already made several attempts directly aimed at shaping, by force, a new regional and continental balance of power (see war against Georgia, in 2008, the annexation of Crimea, in 2014, and an extensive set of military actions against Ukraine), Russian plans and actions are legitimately worrying NATO and, above all, the small or medium-sized countries on the Eastern border of the North Atlantic Alliance. Starting mainly in 2014, Russian aggressiveness generated some significant reactions within NATO, including the political decision to increase defence budgets and deploying (mainly by rotation) military forces belonging to Western member states in the directly threatened countries. These countries (the three small Baltic republics, Poland and Romania) are also strengthening their defensive capabilities, buying new weapons systems, and by hosting or organising NATO defensive exercises. But all these deterrents are costly, and implementing them is time-consuming. It is for these reasons that the article examines the political- strategic necessity of implementing national policies aimed at quickly generating and consolidating potent popular militias. These militias, which are an obvious embodiment of a very strong political will at the national level, might be, if properly used, an extra significant deterrent, directly telling Putin’s regime it has no real chance of winning a quick and cheap victory, if it behaves aggressively against states on the Eastern rim of NATO. At this very moment, more than ever before (at least for almost 30 years since the end of the Cold War), NATO is confronted with the openly aggressive foreign policy, strategic plans and strategic actions of the Russian Federation.