Today countries participating in space activities, share serious concerns about militarization of space. The defense of space can become an important issue in the international arena, because counteracting emerging threats will probably be associated not only with the development of technology and operational capabilities, but also with the creation of political alliances or attempts at international agreement on certain “rules of the game” for space operations. Ultimately, the growing importance of “space for defense” creates the need for “defense of space”. Individual countries remain the main actors in the field of space defense. Military strategies are defined at national level, and the development and exploitation of military space assets are managed by national organizations. Today, most European countries recognize space as a strategic area, next to land, sea, air and, increasingly, cyberspace, but they have adopted different policies and doctrines depending on their sensitivity, priorities and concerns. European space forces also have different governance structures with significant differences in the distribution of roles and responsibilities, including space agencies and private entities.