De Mot, Jef; Fon, Vincy; Parisi, Francesco --- "Customary International Law" [2011] ELECD 1074; in Parisi, Francesco (ed), "Production of Legal Rules" (Edward Elgar Publishing, 2011)

Book Title: Production of Legal Rules

Editor(s): Parisi, Francesco

Publisher: Edward Elgar Publishing

ISBN (hard cover): 9781848440326

Section: Chapter 16

Section Title: Customary International Law

Author(s): De Mot, Jef; Fon, Vincy; Parisi, Francesco

Number of pages: 16

Extract:

16 Customary international law
Jef De Mot,* Vincy Fon and Francesco Parisi



1. Introduction
Given the absence of a world legislature and the cost of forming and ratifying
multilateral treaties, customary law has played a fundamental role in governing
relationships among sovereign states in both historical and modern settings.
Despite some assertions of its diminishing importance (see e.g. van Hoof, 1983),
today customary international law is playing an increasingly prominent role
in the international legal system (see e.g. Jiménez de Aréchaga, 1978; Lepard,
2010). For example, the customary law of human rights has flourished, many
crimes under international law are defined primarily by customary law and
customary international law plays an increasing role in the protection of the
environment (see Lepard, 2010). In this chapter, we focus on contributions that
consider the process of formation and evolution of customary international law.
This process differs from the process of formation and evolution of other sources
of law. Rather than through political deliberation or adjudication, the rules of
customary international law emerge gradually through states' independent and
spontaneous adherence to certain behavioral standards.
This chapter is structured as follows. In Section 2, we give a brief overview of
the relatively few principles that govern the formation of customary international
law. We discuss the two formative elements for an enforceable custom to emerge.
We also discuss the persistent-objector and subsequent-objector doctrines,
which allow states to avoid the binding force of customary international law.
Section 3 contrasts traditional ...