Let's Start with the Basics: Customary International Law in Judgments of ICJ

Welcome to the first post talking about customary international law.

Introduction

We all know that there are five sources of international stipulated under Article 38 of ICJ Statute; international conventions, customary international law, general principles of law, highly qualified publicists and precedents. While the first source of international law has been pretty much codified in the 1969 Vienna Conventions on the Law of Treaties, the requirements and formation of customary international law can only be found in international cases decided by International Court of Justice (ICJ). However, the International Law Commission (ILC) have concluded its work on identification of customary international law in 2016. Besides ILC, International Law Association (ILA) have also studied this matter in 2000.

In light of this background, the topic of customary international law would be divided into two parts. The first one – this one – will discuss the formation of customary international law found within judgements of ICJ. The second part will discuss the formation of customary international law according to ILC and ILA.

In this post, there will be four cases presented. At the end of every section, there will be keywords to help you understand.

North Sea Continental Shelf case 1969

In the North sea continental shelf case (1969), the main dispute was the status of equidistant principle in delimiting continental shelf as a customary international law. The dispute was between German, Denmark, and Netherlands. Germany and Denmark and Germany and Netherlands had previously agreed on delimitation boundaries. In the 1969 North Sea Continental Shelf case, these States were trying to delimit continental shelf beyond the partial boundaries that previously had been agreed upon.

In delimiting beyond agreed partial boundaries, Denmark and Netherlands had concluded negotiation process and wanted to use equidistant principle in doing so. Germany, on the other hand, stated that this principle could not be enforced in this situation due to the natural characteristic of its coastline. Instead, Germany argued that delimitation of continental shelf should be based on “just and equitable share”. Germany added that if this principle were to be enforced, Germany would not receive just and equitable share.

To support their claim, Denmark and Netherlands relied on the 1958 Geneva Convention on High Seas which supported their claim of using equidistant principle. However, Germany had only signed the convention. Thus, Denmark and Netherlands request the ICJ to determine whether or not the 1958 Geneva Convention on High Seas had become customary international law.

ICJ stated that there are two requirements for formation of customary international law: state practice and opinio juris sive necessitatis. State practice must be widespread and representative, meaning that such rule is considered as customary by affected States.

"Not only must the acts concerned amount to a settled practice, but they must also be such, or be carried out in such a way, as to be evidence of a belief that this practice is rendered obligatory by the existence of a rule of law requiring it........... The States concerned must therefore feel that they are conforming to what amounts to a legal obligation."

ICJ then gave an example of what cannot be construed as customary international law.

"There are many international acts, e.g., in the field of ceremonial and protocol, which are performed almost invariably, but which are motivated only by considerations of courtesy, convenience or tradition, and not by any sense of legal duty.”

In this case, the 1958 Geneva Convention on High Seas had only been ratified by few States and German, as an affected State, had not ratified the convention. This means that at that time, this convention had not yet achieved widespread and representative state practice. ICJ furthermore elaborated the customary status of Article 6 as follows

"Article 6 is one of those in respect of which, under the reservations article of the Convention (Article 12) reservations may be made by any State on signing, ratifying or acceding, – for speaking generally, it is a characteristic of purely conventional rules and obligations that, in regard to them, some faculty of making unilateral reservations may, within certain limits, be admitted; whereas this cannot be so in the case of general or customary law rules and obligations which, by their very nature, must have equal force for all members of the international community......."

Hence, ICJ concluded that equidistant principle had not become a part of customary international law at the time of the judgement

North Sea Continental Shelf 1969

State practice, opinio juris sive necessitatis, widespread and representative.

Colombian-Peruvian Asylum case, 1950

The criteria of state practice forming customary international law is also elaborated in Asylum case 1950 between Colombia and Peru. Besides tackling the issue of criteria, Asylum case also tackled issue on formation of regional custom and–possibly–persistent objector.

a. Formation of Regional custom

In 1948, Colombian government granted diplomatic asylum to Haya de la Torre, leader of American People’s Revolutionary Alliance. Colombia based its action on Article 2 of Convention on Asylum and regional custom in Latin America. Peru, of course, contended. Thus the question of such rule’s existence arose. In its attempt to justify its action, Colombia cited the Montevideo Convention of 1889 on International Penal Law, the Bolivarian Agreement of 1911, the Havana Convention of 1928, the Montevideo Convention tahun 1933 and several preceeding cases as practice of customary international law. Colombia particularly emphasized the Montevideo Convention 1933 which had never been ratified by Peru.

In regards to formation of regional custom, ICJ established that customary international law must have a ‘consistent and uniform practice’. Major inconsistencies in practice of a rule would prevent formation of customary international law. Despite the references given by Colombia, ICJ ruled that granting diplomatic asylum has no consistent practice. In its own word, ICJ stated:

“the facts brought to the knowledge of the Court disclose so much uncertainty and contradiction, so much fluctuation and discrepancy in the exercise of diplomatic asylum and in the official views expressed on different occassion...”

Not to mention that there were only a few States that ratified the Montevideo Convention 1933. Hence, it did not reflect Latin America’s consensus on granting diplomatic asylum.

Note that major inconsistencies means that there is so much uncertainty, contradiction, fluctuation, and discrepancy. Following this criteria stipulated by the Court, it is safe to assume that minor inconsistency – the ones that do not have as much uncertainty, contradiction, fluctuation, and discrepancy – would not hamper formation of customary international law.

b. Persistent objector

Persistent objector is a State which rejected a practice of customary international law since the very beginning of its formation. ICJ decided that in any event such rule on diplomatic asylum existed in Latin America as customary international law, Peru would not be bound to it. This is due to the fact that Peru had previosly refused to be bound by such rule.

This rule, however, is contested by many due to the fact that there is a hint of ‘consent’ in customary international law. the rule of persistent objector seem to gave States the ability to opt out on a rule, much like a State could choose to not ratify a convention or to reserve a specific provision of the convention.

Kelsen, Birerly, Fitzmaurice, D’Amato, and Alexidze agreed that consent is not the basis of obligation in international law. After concluding their works, Charney then formulate his position on this matter: if a rule of customary international law is based on consent, the category of persistent objector is serving to purpose since the dissenting States will not be bound whether or not objection is persistent. If customary international law is not based on consent, then States will be bound regardless of their claim as ‘persistent objector’.

Colombian-Peruvian Asylum Case 1950

Consistent and uniform practice, Regional custom, Persistent Objector

Anglo-Norwegian Fisheries case 1951

The main issue of this case was whether or not Norway’s method in establishing its coastline and territorial sea along its fjords and skjaersgaard justified under international law. United Kingdom contended that the ten-mile rule had achieved status as customary international law. Hence, Norway’s method was not acceptable under international law. ICJ then ruled in favor of Norway, stating that Norway was a persistent objector of ten-mile rule.

Apparently, Norway had stated its rejection towards ten-mile rule through its Minister of Foreign Affairs in 1870. The statement is as follows.

“In spite of the adoption in some treaties of the quite arbitrary distance of 10 sea miles, this distance would not appear to me to have acquired the force of international law. Still less would it appear to have any foundation in reality…”

Military and Paramilitary Activities in and against Nicaragua, 1986

The main dispute between United States and Nicaragua in 1986 was whether or not United States was involved in supporting two armed opposition groups in Nicaragua named the Fuerza Democratica Nicaragüense (FDN) and the Alianza Revolucionaria Democratica (ARDE). This act of supporting the armed opposition was evident in United States press, Congress, and also 1983 Budgetary legislation.

“...after an initial period in which the "covert" operations of United States personnel and persons in their pay were kept from becoming public knowledge, it was made clear, not only in the United States press, but also in Congress and in official statements by the President and high United States officials, that the United States Government had been giving support to the contras, a term employed to describe those fighting against the present Nicaraguan Government. In 1983 budgetary legislation enacted by the United States Congress made specific provision for funds to be used by United States intelligence agencies for supporting "directly or indirectly. military or paramilitary operations in Nicaragua".

United States asserted that ICJ did not have jurisdiction over this dispute based on the Vandenberg reservation made in 1946. This reservation provided that ICJ’s compulsory jurisdiction over United States would not extend to disputes arising under multilateral treaty unless either all the part to the treaty affected by the decision were also parties to the case before the Court or the United States specially agreed to jurisdiction. ICJ accepted this contention and instead relied on customary international law of non use of force and non intervention

ICJ upheld its previous judgment in North Sea Continental Shelf which stated that there are two requirements for the formation of customary international law. H.C.M. Charlesworth concluded that ICJ acknowledged acceptantce of treaty obligation, statements of ILC, and judgments of ICJ as a form of state practice. contrasting it to the opinion of judge D’Amato.

“Unlike jurists such as D'Amato, who regard only actions which have physical consequences as state practice, the Court accepts General Assembly resolutions and resolutions of other international organisations, particularly those in which Nicaragua and the United States participated, as forms of state practice.”

H.C.M. Charlesworth furthermore concluded that there is a lack of explanation of what can be construed as state practice based on the Judgement in paragraf 202 that stated: “The existence in the opinio juris of States of the principle of non-intervention is backed by established and substantial practice.”

However in the wording of the judgment, ICJ clearly stipulated in paragraph 189, 191, and 192 that General Assembly resolutions and resolutions of other international organizations are a form of opinio juris sive necessitatis. Hence, even though the judgement of ICJ in Nicaragua did not explain state practice as thoroughly as opinio juris sive necessitatis, the conclusion that General Assembly resolutions and resolutions of other international organizations would further vague the distinction between two criteria.

In Nicaragua, ICJ elaborated the relationship between customary international law and international conventions. This is due to United States’ argument that when a rule has been enshrined in a treaty, it ceased to have it’s customary character. In response to this, ICJ explained that there are two situations.

a. Where two sources of international law appear identical in content

b. Where customary international law and treaty obligations have a distinction even though they fall about the same subject matter. This can be seen in paragraf 180:

“The United States observed that the multilateral treaties in question contain legal standards specifically agreed between the Parties to govern their mutual rights and obligations, and that the conduct of the Parties will continue to be governed by these treaties, irrespective of what the Court may decide on the customary law issue, because of the principle of pacta sunt servanda.”

In the first situation, ICJ stipulated that customary international law still existed even though it had been codified or incorporated into a certain provision of a treaty. This means that both customary international law and treaty obligation will be applied to States who have ratified such treaty. In the second situation, ICJ stipulated that the provision contained within the treaty will serve as lex specialis.

Military and Paramilitary Activities in Nicaragua

Acceptance of treaty obligation, statements of ILC, GA Resolutions, IO Resolutions, existence of customary international law alongside treaty law

Conclusion

Aforementioned cases have elaborated how a customary international law is formed; through state practice and opinio juris sive necessitatis. State practice must be widespread and representative, as can be seen in the example of ratification of the 1958 Geneva Convention on High Seas. After being established, customary international law must be performed in a consistent and uniform manner.

Customary international law provides exception. When a State, since the start of the formation of customary international law have rejected the rule, it will not be bound by such rule. However, this rule has been contested by many due to the hint of consent.

In finding state practice, one may rely on acceptance of treaty obligation, statements of ILC, and judgments of ICJ as forms of state practice as provided in Military and Paramilitary Activities in Nicaragua. On the other hand, opinio juris sive necessitatis can be found in General Assembly resolutions and other international organizations resolutions. Military and Paramilitary Activities in Nicaragua also provided that customary international law and international conventions exist side by side.

REFERENCES

1. Colombian-Peruvian asylum case, Judgment of November 20th, 1950: I.C.J. Reports 1950

2. Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment. I.C.J. Reports 1986

3. North Sea Continental Shelf Cases (Federal Republic of Germany v. Denmark; Federal Republic of Germany v. Netherlands) , I.C.J. Reports 1969

4. Anglo-Norwegian Fisheries, U.K. v. Norway, Order, 1951 I.C.J. 117

5. Olufemi Elias, "Some Remarks on the Persistent Objector Rule in Customary International Law", the Denning Law Journal

6. Andrew T. Guzman, "Saving Customary International Law", 27 Michigan Journal of International law 1 (2005)

7. H.C.M. Charlesworth, "Customary International Law and the Nicaragua Case", Australian Yearbook of International Law