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.

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.