The idea of citizen soldiers can be dated to ancient times. Through the process of democratization it has gotten a new grounding, beginning with the evolution of modern states. The author of this article is making a short but general overview of the basic concepts of this evolution, albeit not in a historical perspective. According to the main premise, it is more a philosophy of the state and general political ideas that allow the military to become the highly skilled, democratically controlled force of soldiers and potential citizens soldiers through the system of national reserves. The force of the reservist based on NATO’s philosophy and strategic concepts is supposed strengthen the regular conscripts and make a liaison with the socio-political civilian sphere of the particular nations. This concept, as is shown, applies to many countries of the Euro-Atlantic community of states, including Poland. Their common denominator lies in the republican idea of democracy and the individual citizens’ responsibility for its nation.