Introduction

Summary

The Introduction outlines the nature of the study and the rationale for undertaking it. It argues that collective self-defence remains under-theorised (and collective self-defence practice under-analysed) despite the increased invocation of it by states in recent years. The Introduction also discusses the book’s methodology, particularly in relation to its focus on state practice and opinio juris as crucial ‘raw materials’ for legal standards in this context. The key facts and findings of the famous 1986 Nicaragua decision of the International Court of Justice are then summarised, because the case is referred to throughout the book. The Introduction concludes with a summary of the structure of the book.