Chapter 1 reviews past scholarly ideals and political realities of a world constitution, focusing on the Covenant of the League of Nations and the Charter of the United Nations. It sketches out the core claims of the book according to which constitutional trends in world politics must be viewed with realistic skepticism and, in that light, can be understood in terms of a process called constitutionalization. This process does not generate the unified constitutional framework typically associated with national constitutions but manifests itself as an inadvertent by–product of piecemeal international treaty making driven by proximate objectives within issue–specific domains. The chapter then presents the major themes and limitations of the contemporary “constitutionalism beyond the state” debate and establishes how a social scientific perspective can add to this legal debate. It concludes with a preview of the book, emphasizing the main theoretical insights and empirical findings.

The logic of democratic power is put to an empirical test in Chapter 6. Having identified treaties as the best observable source of international rules, this chapter tests the democratic power argument for international rule–based cooperation systematically in the context of international treaty making, which involves three stages – negotiations, commitment, and compliance. This statistical analysis is based on a dataset of seventy–five international treaties adopted between 1945 and 2008 and is complemented with insights from the International Covenant on Civil and Political Rights. The results reveal consistent and robust empirical patterns regarding states’ willingness and ability to cooperate over international treaties, which are generalizable across treaties, issues, and the stages of treaty making. The analysis confirms the centrality of the democratic powers as the chief promoters and adherents of international rules that gradually but inadvertently contribute to the constitutionalization of world politics.

Chapter 2 conceptualizes constitutional properties in both domestic and international settings. Drawing on domestic experiences, it defines constitutions, whether written or unwritten, as a special category of institutions that provide fundamental rules (of recognition and change) as well as rules that regulate a community of members, their relations, and their rights and duties (rules of conduct). It then identifies corresponding constitutional properties in the international setting, acknowledging the limits of this analogy. While still embryonic, international rules with constitutional relevance are especially apparent in those binding treaties of public international law that are universal in intended participation, global in scope, and of substantive importance. These rules are underpinned by the principle of sovereignty, which provides for their stability and superiority. International constitutional rules define states as the prime members, organize inter–state relations in an anarchical environment by concentrating authority in circumscribed domains, and lay out rights and duties that enable collective action and set standards of appropriate behavior.

Operating against anarchy rather than hierarchy, international constitutionalization is a highly contested but unintended political process. It is a by–product of international treaty making, which is intended to create fairly specialized rules within issue–specific domains. Approximating the evolutionary pathway, this process nonetheless generates a less unified international constitutional framework than in the national setting. An examination of international constitutional developments (along the five core constitutional elements) reveals that formalization of international rules through treaties has become standard in the post–1945 period. Sovereignty has developed into the fundamental international principle, extending the circle of members to include newly emerging states. Relations among states have deepened to enhance inter–state cooperation, and rights and duties have further reproduced inequalities among states. The chapter concludes by stressing the inadvertent constitutional consequences of international treaty making, which leads to the constitutionalization trap.

Moving from the grand and abstract theme of international constitutionalization to the more tangible and observable process of international rule making, Chapter 5 analyzes states’ motives for cooperating over international rules that form the unintended basis of international constitutionalization. It lays out the logic of democratic power, according to which states that are both democratic and powerful (democratic powers) combine the willingness and ability to promote international rules. Because democracies are rule–based, they understand the value of operating through rules and doing so is consistent with their domestic operations. Insofar as they are also powerful, democracies are able to advance their rule–based approach at the international level to shape rules according to their interests and values, which makes it easier for them to commit to and follow those rules. Democratic powers are thus decisive for international rule–based cooperation. States that lack either one or both of these prerequisites are less supportive of institutionalized cooperation and thus constitutionalization in world politics.

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.

Constitutionalization encompasses a variety of ways in which constitutional rules emerge and change. Chapter 3 addresses the emergence and development of constitutional rules in the national context. It begins with a conceptual discussion of constitutionalization, defined as any process that brings about and changes constitutional rules. Spanning a spectrum between two ideal–type revolutionary and evolutionary pathways, constitutional processes vary with regard to frequency, intensity, output, and means of change, as well as the underlying political intentionality and contestation. The variability of constitutionalization is demonstrated empirically through a systematic analysis of national constitution–making in the United States, Sweden, and Britain in terms of the five constitutional elements identified in Chapter 2, emphasizing their similarities and differences. While this analysis will not be entirely novel to the comparative constitutional law and politics readership, it is an important building block for conceptualizing constitutionalization in the international setting.