Public Law Studies Quarterly

Interpretation of Customary International Law: From its Existence to Functionality

Articles in Press

Document Type : Article

Authors

Abasali Kadkhodaee 1
Seyed Hossein Sadat Meidani 2
Kasra Pourmikaeil 3

1 Prof., Departement of Public Law, Faculty of Law and Political Science, University of Tehran, Tehran, Iran

2 Assistant Prof., Department of International Law, School of International Relations Ministry of Foreign Affairs, Tehran, Iran

3 Ph.D. Candidate in International Law, Faculty of Law and Political Science, University of Tehran, Tehran, Iran

https://doi.org/10.22059/jplsq.2024.379337.3566
Abstract
It is a fact that international law does not contain any general prescriptions regarding interpretation. While some interpretative principles and rules have become reference points, international law does not require a unified interpretation process for all sources of international law, and rules of interpretation may vary based on the source of law. This article sheds light on these applicable rules that can be used when interpreting customary rules, arguing that the interpretation process is an entirely separate operation from identification and both play their particular role in the life cycle of customary rules. However, due to its fluidity and unwritten nature, applying interpretative approaches and elements to customary rules requires its formulation compared to treaty law. This article argues that contextual interpretation is the appropriate approach to interpreting CIL. Contextualism is not only an overarching principle in identifying CIL but also a proper method for interpreting it.  Subsequent practice and other relevant rules of international law are also pertinent elements that could be applied in interpreting customary rules.

Keywords

identification of customary international law
interpretation of customary international law
interpretation of international treaty
Subjects

  1. A) Books

    1. Ammann, O. (2019). Domestic Courts and the Interpretation of International Law. Leiden: Brill | Nijhoff.
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    3. Bos, M. (1984). A Methodology of International law. Amsterdam: NORTH HOLAND.
    4. Dorr, O., & Schmalenbach, K. (eds). (2018). Vienna Convention on the Law of Treaties A Commentary. Second Edition. Heidelberg: Springer
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    6. Koskenniemi, M. (2006). From Apology to Utopia. Cambridge: Cambridge University.
    7. Marmor, A. (2005) Interpretation and Legal Theory. 2nd ed, Oxford: Hart Publishing.
    8. Merkouris, P. (2015). Interpretation of Customary International Law by Reference to the Customary Law Equivalent of Article 31(3)(c) (Article 31(3)(c) CIL)". In Article 31(3)(c) vclt and the Principle of Systemic Integration. Leiden: Brill | Nijhoff.
    9. Orakhelashvili, A. (2008) The Interpretation of Acts and Rules in Public International Law. Oxford: Oxford University.
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    1. B) Articles
    2. Bhala, R., & Witmer, E. (2019) Interpreting Interpretation: Textual, Contextual, and Pragmatic Interpretative Methods for International Trade Law. Connecticut Journal of International Law, 35 (2), 58.
    3. Chasapis Tassinis, O. (2020). Customary International Law: Interpretation from Beginning to End. European Journal of International Law, 31 (1), 235–267.
    4. Di Marco, R. (2022) Customary International Law Identification versus Interpretation, In The Theory, Practice, and Interpretation of Customary International Law (The Rules of Interpretation of Customary International Law). MERKOURIS, P., KAMMERHOFER, J., & ARAJARVI, N. (eds). Cambridge: Cambridge University, 414.
    5. Endicott, T. (1994). Putting Interpretation in Its Place. Law and Philosophy,
    6. Fortuna, M. (2022). Interpretation of Rules of Customary International Law, Their Identification and Treaty Interpretation’, In The Theory, Practice, and Interpretation of Customary International Law (The Rules of Interpretation of Customary International Law). MERKOURIS, P., KAMMERHOFER, J., & ARAJARVI, N. (eds). Cambridge: Cambridge University, 393.
    7. Gourgourinis, A. (2011). The Distinction between Interpretation and Application of Norms in International Adjudication. Journal of International Dispute Settlement, 2 (1), 31.
    8. Herdegen, M. (2020). Interpretation in International Law’ in: Rudiger WLLFURM and Anne PETERS (eds), MPEPIL. online edn, Oxford: Oxford University.
    9. Merkouris, P. (2017). Interpreting the Customary Rules on Interpretation. International Community Law Review, 19 (1), 126–155.
    10. Merkouris, P. (2022) Interpreting Customary International Law, You’ll Never Walk Alone, In The Theory, Practice, and Interpretation of Customary International Law (The Rules of Interpretation of Customary International Law). MERKOURIS, P., KAMMERHOFER, J., & ARAJARVI, N. (eds). Cambridge: Cambridge University, 347.
    11. Milleva, N. (2022). The Role of Domestic Courts in the Interpretation of Customary International Law, How Can We Learn from Domestic Interpretive Practices? In The Theory, Practice, and Interpretation of Customary International Law (The Rules of Interpretation of Customary International Law). MERKOURIS, P., KAMMERHOFER, J., & ARAJARVI, N. (eds), Cambridge: Cambridge University.
    12. Pellet, A. (2018). Canons of Interpretation under the Vienna Convention, In Between the Lines of the Vienna Convention? Canons and Other Principles of Interpretation in Public International Law. KLINGLER, J., PARKHOMENKO, Y., & SALONIDIS, C.(eds). Netherland: Wolters Kluwer.
    13. Talmon, S. (2015). Determining Customary International Law: The ICJ’s Methodology between Induction, Deduction and Assertion. European Journal of International Law, 26 (2), 417–443.
    14. T, (2006). Customary International Law. in Rudiger WOLLFURM and Anne PETERS (eds), MPEPIL. online edn, Oxford: Oxford University.
    15. I, (2018). Authorative Interpretation in International law’ in Helene FABRI RUIZ (ed), Max Planck Encyclopedias of International Procedural Law. online ed, Oxford, Oxford University.
    16. Waibel, M. (2011). Demystifying the Art of Interpretation. European Journal of International Law, 22 (2), 571.
    17. Wood, M., & Sender, O. (2022). Between theory, practice, and ‘interpretation’ of customary international law. https://cil.nus.edu.sg/blogs/between-theory-practice-and-interpretation-of-customary-international-law/

     

    1. D) Cases
    2. Accordance with International Law of the Unilateral Declaration of Independence in Respect of Kosovo, Advisory Opinion, ICJ Rep 2010
    3. Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea, Merit (Nicaragua v. Colombia) ICJ Rep 2022
    4. Arrest Warrant of 1 I April 2000 (Democratic Republic of the Congo v. Belgium), Judgment, I.C.J. Reports 2002
    5. Continental Shelf (Libyan Arab Jamahiriya/Malta), Judgment, I. C.J. Reports 1985
    6. Factory at Chorzow, Dissenting opinion of Judge Ehrlich (Jurisdiction, 1927) PCIJ Series A No.9
    7. Frontier Dispute (Burkina Faso/Republic of Mali), Judgment, I.C.J. Reports 1986
    8. Iran-United States Claims Tribunal, Federal Reserve Bank of New York v Bank Markazi, Case A 28 (2000) 36 Iran-US Claims Tribunal Reports 5
    9. Jurisdictional Immunities of the State (Germany v. Italy: Greece intervening), Judgment, I.C.J. Reports 2012
    10. Kasikili/Sedudu Island (Botswana/Namibia), Judgment, I. C. J. Reports 1999
    11. Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, Advisory Opinion, I.C.J. Reports 2019
    12. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I. C.J. Reports 1996
    13. Legality of Use of Force (Serbia and Montenegro v. Belgium), Preliminary Objections, Judgment, I.C.J. Reports 2004
    14. Legrand (Germany v. United States of America), Judgment, I. C. J. Reports 2001
    15. Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America). Merits, Judgment. I.C.J. Reports 1986
    16. North Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands) Judgment of 20 February 1969 [1969] ICJ Rep. 3, Dissenting Opinion of Judge Tanaka
    17. North Sea Continental Shelf Cases (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands) (Merits) [1969] ICJ Rep
    18. Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, I.C.J. Reports 2010
    19. Reservation to the Convention on genocide, Advisory opinion ICJ reports1951
    20. Territorial Dispute (Libyan Arab Jamahiriya/Chad), Judgment, 1. C. J. Reports 1994

     

    1. E) Documents
    2. https://www.un.org/en/ga/sixth/75/pdfs/statements/ild/ola.pdf
    3. ILC, ‘Draft Conclusions on Identification of Customary International Law, with Commentaries’ (30 April–1 June and 2 July–10 August 2018) UN Doc A/73/10
    4. ILC, ‘Draft Conclusions on Subsequent Agreements and Subsequent Practice in Relation to the Interpretation of Treaties, with Commentaries’ (30 April–1 June and 2 July– 10 August 2018) UN Doc A/73/10, reproduced in [2018/II – Part Two] YBILC 11
    5. ILC, ‘Report of the International Law Commission on the Work of its 63rd Session’ (26 April–3 June and 4 July–12 August 2011) UN Doc A/66/10
    6. Yearbook of the International Law Commission 1966, Volume II, reports of the Commission to the General Assembly, document A/6309/Rev.l
Public Law Studies Quarterly

Articles in Press, Accepted Manuscript
Available Online from 22 November 2026

  • Receive Date 26 July 2024
  • Revise Date 02 October 2024
  • Accept Date 11 November 2024

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