Regional and General International Law

In the post-Cold War era, positivist scholars and practitioners have generally regarded regional international law as merely a subset of particular international law whose validity depends on general international law. As consensus on universal legal values erodes and regional rules proliferate across nearly every area of international law, this assumption is increasingly under pressure. Against this backdrop, Regional and General International Law provides a framework for understanding the distinct legal significance of regional international law and its complex interaction with general international law.

The monograph's central claim is that regional international law as a legal category distinct from other forms of particular international law plays a key role in shaping general international law, while general international law remains indispensable for enabling and safeguarding regional plurality. To substantiate this claim, the book draws on examples from all regions and a wide range of legal fields, making three key contributions: it develops criteria for identifying a "region"; demonstrates that regional rules and practice play a distinct role in shaping international law, often creating a "triple challenge" to general international law that sets them apart from other forms of particular international law; and proposes a three-step approach, grounded in the secondary rules of international law, to address this triple challenge. This three-step approach facilitates the assessment of the validity, content, and limits of regional rules and practices, as well as their potential impact on the development of general international law.

Regional and General International Law shows that recourse to secondary rules enables all states to contest, shape, and influence both regional and general international law. Regional and General International Law offers a theoretically grounded, methodologically rigorous, and practice-oriented approach that enables scholars, practitioners, and students to understand and constructively engage with the evolving relationship between regional and general international law in a multipolar world.