The main claim of this chapter is that planetary defense against asteroids cannot be implemented under a decentralized model of democratic global governance, as espoused elsewhere in this book. All relevant indices point to the necessity of establishing a centralized global political authority with legitimate coercive powers. It remains to be seen, however, whether such a political system can be in any recognizable sense democratic. It seems unconvincing that planetary-wide physical-threat, all-comprehensive macrosecuritization, coupled with deep transformations of international law, global (...) centralization of core decision-making powers, de-stigmatization of nuclear weapons and the like can proceed, succeed, and be implemented in a non-hierarchical international system where planetary defense constitutes only one regime among many, and where states basically remain the decisive actors. Although rationally and scientifically robust, the project suffers from oversimplification, as well as naivety with respect to how both international and domestic politics works. Among other topics, this chapter discusses problems associated with the rule of law and constituent powers, political representation and sources of legitimacy, conditions of multilevel collective action, or limits of theoretical idealization. The general message is that the planetary defense community needs to be more aware of the social and political context of its own enterprise. (shrink)