Chapter 7 returns to the larger topic of constitutionalization in world politics by addressing its contemporary challenges and implications. Despite the strong evidence presented on the relationship of democracy, power, and international rule–based cooperation, recent events raise serious doubts regarding the constitutionalization of world politics. Current real–world developments challenge the continuing relevance of international treaty making, the support for cooperation from the major powers, the stability of democratic principles, and therefore the viability of constitutionalization itself. This chapter lays out those trends and puts them into longer–term perspective, arguing that, although they pose serious threats in world politics, they should not be overstated. The prospects of constitutionalization must be instead approached with realistic skepticism. What today appears as an impediment to constitutionalization may not be so consequential when viewed over the long run. A realistic perspective must therefore take global constitutionalization both skeptically and seriously.