Sir Michael Wood, Omri Sender
- Customary international law — Codification — Opinio juris — State practice
Published under the auspices of the Max Planck Foundation for International Peace and the Rule of Law under the direction of Rüdiger Wolfrum.
1 The practice of States plays a number of important roles in international law. This entry, however, is chiefly concerned with State practice as an element in the formation and identification of rules of customary international law, one of the principal sources of international law . State practice is creative, or expressive, of customary international law, but only in so far as it is undertaken with a legal conviction (acceptance as law, or opinio iuris ). A rigid distinction between State practice and opinio iuris as two independent constituent elements of...