Identification of Customary International Law – Discuss


What are customary international laws and why are they important than treaties?

Customary international laws are certain sources of international laws listed by article 38 Para 1of the statue of ICJ. These customs were required by international laws even when we already have the concept of treaties. There are specifically two reasons for the same. Firstly, the process of making treaties or rules is itself regulated by international customary law. Therefore it becomes very important to understand the customary international laws before we can go to treaties. Secondly, these international customary laws are binding on certain organizations and thus can be used by the court for applications. Hence this is the reason that customary international laws are also called general international laws. On the other hand, these treaties are binding only on the contracting parties and hence they do not have a much bigger scope as that of customary international law[1].


In the year 2012, International Law Commission (here ILC) during its 64th session decided to introduce a topic on its current programme of work and it was called “formation and evidence of customary international law”[2] and wood was made its the special rapporteur. The topic was changed to “identification of customary international law” during its 65th session.[3]


Woods in his first report tried to highlight the previous work of ILC and from that he identified the main aim of the topic and it was to provide guidance to all those who are trying to apply the rules of international customary law besides their application in some of the concrete cases. This topic was also aimed at highlighting the status of international customary laws and their existence even if some of the historical developments take place.


While working on the topic woods presented some arguments:

  • He presented a comparative analysis of treaties and customs. For that he studied the relation of customary laws with that of other sources listed in article 38 of the statutes if ICL along with treaties and general principles. He analyzed that treaties are a much bigger source of international law than customs.
  • There are some fields where there exist no codifications but still, in all those area these international customs govern all those subjects about which the codification is silent. These customs have full capacity to fill the gaps which are left by these treaties and even help these treaties for achieving new interpretations. Thus it can be decided by international courts that in all those cases where no treaties can opt then these customs should be used.


The 67th session of the International Law Commission was organized under the chairmanship of Narinder Singh (India) between 4th May and June 5 and from 6th July to 7th august[4]. The drafting committee ended up drafting 16 conclusions on this topic which have got it’s approval in the year 2016 after the first reading.

Besides that the committee has also adopted various drafts and these drafts were on the topics:

  • Protection of atmosphere
  • Crimes against humanity
  • Agreements on the interpretation of treaties
  • Protection of nature in relation to arms conflicts
  • Foreign diplomat immunities from judicature
  • How treaties can be applied provisionally
  • The most favour nation clause etc.

Some of the topics were just initially drafted others were fully drafted while some were provisionally adopted. Along with that certain new topics like jus cognes were also added.


Draft conclusion 1 which deals with the basic introduction that is how are we going to deal with the existence of international customary laws.

Draft conclusion 2 deals with the basic approach that is to be followed, towards the customary international laws. it deals with the determination of the existence of customary law and to ascertain if there is a general rule of forming laws.

Draft conclusion 3 deals with the assessment of the evidence of two elements. Firstly we need to find out the evidence that proves that can show that there exists a general practice which has been accepted as law. Secondly, ascertain each and every element.

Draft conclusion 4 deals with the various sources that could be responsible for the formation of customary international laws. These can be general practices of the states, a practice followed by internal organisations. Eliminating the role of actors as a source but they may also be the source when assessing certain specific practices.

Draft conclusion 5 deals with practices followed by the state that becomes a practice of customary international laws. These state practices can be by participating in the exercise of executive, legislative functions or judicial functions.

Draft conclusion 6 deals with forms of practices that exist in the state. These activities range from physical or verbal or can be under certain circumstances. It can also be diplomatic acts, and acts of correspondence, or various other acts.

Draft conclusion 7 deals with the assessment of the practices that exist in a state. Like if an activity is less likely to be practiced in a state while more in other than choosing one or reducing it.

Draft conclusion 8 deals with the nature of the practice. That means the practices added should be very general in nature and must not be just a habit or usage.

Draft conclusion 9 deals with the requirement of accepting these general practices as law. This here means that it should not be taken just because it is a practice but should be taken from the legal view, to be accepted as a law.

Draft conclusion 10 deals with the evidence that the practice is taken as a law by the acceptance of all and not just by the opinion of states etc.

Draft conclusion 11 deals treaties and all the codified rules and regulations.

Draft conclusion 12 deals with all the resolutions adopted by international bodies, through organisations and conferences.

Draft conclusion 13 deals with the decisions made by all the courts as well as the tribunals.

Draft conclusion 14 deals with the teachings of all the experts in the field. It includes their opinions and statements.

Draft conclusion 15 deals with the objection rules that can be brought by any of the participating states if it is not considered as a general practice but they have to be very specific in their approach and statements. If any state objects then the practice cannot be considered as a law.

Draft conclusion 16 deals with the particular type of custom and rules regarding it, whether it can be added in the customary laws. If certain custom is applicable only to a particular number of states then the applicability of the custom.

All these drafts focus on the most important issues with respect to the customary international laws[5].


International law commission – 70th session in year 2018

  • The commission has adopted the identification of international customary international law on their second reading along with all the commentaries have also been adopted.
  • The commission has also decided that there will be a general assembly as per Article 23 of its statue, whose work would be to form note of resolution of the draft conclusion of customary international laws. besides this their work also includes annexing a resolution to the draft, spreading the resolution as much as possible, praise the draft conclusion that has been prepared and inform it to all the states identified by customary international law and follow up all the new suggestions.

General Assembly conclusions

As per resolution 73/203 of year 2018

  • To welcome the resolution prepared by customary international law and adopt the conclusion draft prepared by them along with the commentaries.
  • To take the note of statements prepared by the 60th as well as 63rd session of the commission.
  • Acknowledge the efforts made by the committee top prepare the digests and encourage the states to make every effort to support the existing publications[6].

[1] Daniel M. Bodansky, The Concept of Customary International Law, 16 MICH. J. INT’L L. 667 (1995). Available at:

[2]Ruwanthika Gunaratne and Public International Law at,  2008


[4] See Report of the International Law Commission on the Work of Its Sixty-Seventh Session, UN GAOR, 70th Sess., Supp. No. 10, at 9, para. 4, UN Doc. A/70/10 (2015) [hereinafter 2015 Report]. Available at

[5] Murphy, Sean D., The Identification of Customary International Law and Other Topics: The Sixty-Seventh Session of the International Law Commission, American Journal of International Law (forthcoming 2015-16). Available at:

[6] See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/724)

This Article is Authored by Rupinder Kaur, B.A.LL.B. Student at Symbiosis Law School, Noida.

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