Introduction

Abstract

Abstract This chapter introduces the analytical framework of the volume. It starts by providing working definitions for secondary rules of international law—with a specific focus on the law of state responsibility in international adjudication—and explains why rules on causation, attribution, the standard and burden of proof, and the standard of review are core secondary rules in international law. The chapter argues that, whilst secondary rules are much more than mere technicalities and, in fact, form the heart of the matter in international adjudication, there is significant variation in their conceptualization and employment by international courts and tribunals. The chapter then outlines the contributions to this volume with respect to the four main types of secondary rules and identifies common challenges in the application of secondary rules in international law across different branches and courts of international law.