Is there space for new sources of international law, or do the existing ones

Merely need improvement?


In 1922 due to the establishment of the Permanent Court of International Justice a commission of jurists was appointed in order to draft a statute to govern the workings of this court. The role it had to play was quite significant since it was the first standing international tribunal to resolve disputes between states. After World War II the PCIJ was replaced by the International Court of Justice adopted the statute of the previous court. Article 38 of this statute provide for the sources of international law. The task of this essay is to examine if there is a need for the creation of new sources of international law besides those provided for in the statute or if the existing ones need improvement to cover all aspects of International law. In order to complete this task we must first examine the existing sources of law discuss their adequacy and then decide if there is space for nee sources to be created.

The Sources Of International Law

As it was already mentioned above, the sources of international law can be found in Article 38(1) of the statute of the International Court of Justice. The following sources are known as the four sources of the international law:

  1. International conventions, establishing rules expressly, recognised by the states
  2. International custom
  3. The general principles of law
  4. Judicial decisions of internat. Court and tribunal and the teachings of the most highly qualified publicists of the various nations

The above mentioned sources of international law can be divided into two categories, the first being formal and the second being material sources. Formal sources are those that constitute what the law is, namely International Treaties, Customary Law and the General principles of law. Material sources are those that designate where the law can be found and these are the judicial decisions and the Juristic teachings.

The international sources of law cannot function independently; the one needs the other for a solid and coherent implementation of justice. The one source uses the other as safety net for filling the gaps of international law so none of these sources independently of the others can adequately reflect the international law.

There are though some areas of international practice that are not regulated by any of the above four sources (five if we consider the teachings of the international law scholars as a separate source), such as in the case of a technological innovation where the time passed was inadequate for the creation of legal rules, or as in the case where there are states objecting to the creation of a law as it will be contrary to their interests like the handful of nuclear States. Therefore it can be argued that the five sources of international law reflect to a large extent the base for the emergence of international legal rules but not all the international legal rules. Article 38 has been much criticised as inadequate, out of date, or ill-adapted to the conditions of modern international intercource.

According to Evans, M. there have been suggestions that the whole concept of ‘sources’ should be replaced by, for example, the ‘recognised manifestations of international law’ it has also been suggested that additional sources of law should be accepted. In reality though no new approach has acquired any endorsement in the practice of states, or in the language of their claims against each others and the international court has in its decisions consistently analysed international law according to the Article 38. But whether many scholars and commentators consider the Article 38 outdated or not it is not so important because the Court remains bound by it. If the International court had identified a significant change in the sources of international court it would have at least taken it into consideration.

Since the court is bound by the Article 38 the five sources of the international law still have significant importance.

Brief Analysis Of The Five Sources Of International Law

International Conventions

Some treaties are the result of codifying existing customary law, such as laws governing the global commons, and jus ad bellum (a set of criteria that are consulted before engaging in war, in order to determine whether entering into war is justifiable). The purpose of international conventions is to establish a code of general application, In order for an international convention to enter into force it must be signed and ratified by a specific number of states, and if the threshold is set too high only few such instruments have a sufficient number of parties to be regarded as international law in their own right.

International conventions are the first of the five sources of international law and are consisted of the treaties signed and ratified by the various states. Such treaties may be bilateral meaning between only two states or multilateral which means between more than two states, between many, most or all states. The multilateral conventions take many years until to be created.

Treaties are the international laws equivalent to statues. A state becomes party to a treaty through the following two steps: through signing the treaty (signature is given by the government). Signing a treaty provides an opportunity to a State to provide its intent to become party to a treaty. The second step is the process of ratification by which a treaty is accepted by the parliament. The Treaty of Lisbon has been signed by all members of the European Union but was not ratified by all states and therefore didn’t come into force. When you ratify a treaty you must not do anything to defeat the object and the purpose of the treaty.

International laws established by treaty will take preference if such an instrument exists. It is also argued however that international treaties and international custom are sources of international law of equal validity. This means that new custom may supersede older treaties and new treaties may override older custom.

An example where the need for synergy of all the sources of international law is obvious is in the case where two states have a dispute and the one has ratified the treaty and the other did not. This means that the treaty cannot be used to settle the dispute. In such a case if there is an earlier treaty that both states are parties to it can be used to settle the dispute otherwise in the absence of a codified law (treaty) the states must refer to the customary law.

A well known example that reflects the above scenario is in the case of the Aegean dispute between Turkey and Greece. Greece signed and ratified a treaty by which it is given the right to extent its nautical miles to twelve from six that are currently. Turkey is opposing to this right that Greece has because Turkey didn’t become party to the treaty and therefore it is not bound by the terms of the treaty.

Therefore, International conventions emerge from the will (with the consent) of contesting states to establish rules expressly, recognised by the states.

A treaty is one of the most evident ways in which rules binding on two or more states may come into existence. In 1969 Vienna Conventions on the law of treaties states the principle of “Pacta Sunt Servanda” every treaty is binding upon the parties to it and must be performed by them in good faith.

Customary Law

Customary law makes sure that there is a minimum standard in the international law, it restrains the states and sets out a minimum set of obligations.

The Customary law has two elements which can be considered as the foundations or the base from which the customary law emerges. The first element is the object to criteria which means the evidence of contact and practice of state. This is the objective element.

In the Asylum case 1950 the International Court of Justice held that in order for a rule to be considered as customary international law it requires constant and usage practice by the states in question. The ICJ held that “The Columbian government must prove that the rule invoked by it is in accordance with a constant and uniform usage practiced by the States in question, and that this usage is the expression of a right appertaining to the State granting asylum and a duty incumbent on the territorial state.

The objective element is satisfied if there is continuity (repetition) therefore is required that the evidence of conduct and practice of state must be continues and repitited, uniformity among state practices or at least extensive and virtually uniform.

In the North Sea Continental Shelf case the ICJ (1969) held that because the states practice is very difficult to be “uniform” they have used the extensive or virtually uniform. The analysis of the ICJ in this case is applicable to custom-creation generally.

The ICJ in the Nigaragua (1986) followed the same attitude as in the NSCS case and ruled that “Not in absolute rigorous” it suffices for the creation of customary law. Through the Nigaragua case there was a conclusion that major inconsistencies in the practice- Large amount of practice which goes against the rule in question and prevent the creation of customary rule. However minor inconsistencies do not prevent the creation of customary rules.

The second element is the subject to criteria (Opinio Juris). This element sets the prerequisite that the State concerned behaves in a way because it believes that is obliged to behave in that way by virtue of the existence of the relevant customary law. But there are two questions concerning customary law. a) How can practise of states developed into customary law if the States have to believe that the rule exists before their acts of practice can be significant for the creation of the rule, b) Is it sufficient if initially States act in the mistaken belief that a rule already exist. (Does a shared mistake produce law?)

In the North Sea Continental Shelf case the court held that the States were acting in the application of the convention and thus from their action no inference could be drawn as to the existence of rule of customary law. They couldn’t show ‘opinio juris’ as the acts of practice are attributed to a motive other than such consciousness.

Both objective and subjective element are needed in order to invoke the customary law. The time factor for the creation of customary law depends on the subject for example the law of the sea it developed over the last 500 years, example ‘cannon shot’ law.

The outer space law is a relatively new law. RES COMMUNIS. It does not mean that because USA was the first State that landed to the moon that it owns the moon.

Customary law is applicable to all States without exception while treaty law is applicable as such only to the parties to the particular treaty.

Although the purpose and aim of the international law is to implement rules that will have a universal status and will be binding upon all the countries some States found ways to deviate from the strict application of the Customary Law and manage to establish certain exceptions that favourite them. There are two exceptions to general customary law.

The first exception is when something called local or special custom exists. A special custom is not concerned with the geographic space. For example in the Right of Passage over Indian Territory case Portugal relied on such custom as regulating the relationship between itself and India. Concerning access to certain Portuguese enclaves in Indian Territory.

A local custom is concerned with the precise geographical location for example the Latin American Countries. At the Asylum case the court said that the party which relies to such a custom must prove that this custom is established in such a manner that is becoming binding to the other party. The Columbian government must prove that the rule invoked by it is in accordance with a constant and uniform usage practiced by the States in question, and that this usage is the expression of a right appertaining to the State granting asylum and a duty incumbent on the territorial state. For any local custom the threshold is higher than customary law.

The second exception to customary law is the persistent objector rule. It is in principle possible for a State which does not accept a rule which is in the process of becoming standard international practice to make clear its opposition to it in which case will be exempted from the rule when it does become a “rule of law” having the status of what is generally called a “persistent objector”.

It was defined in the reasoning of Asylum case. (Peru had a statues of persistent objector) and in the earlier case of Fisheries between UK and Norway. The position today is that “the persistent objector” should not apply to customary law therefore it only applies to local custom.

Article 38 contains the injunction that the court should apply ‘international custom, as evidence of a general practice accepted as law’. This definition of customary law is unsatisfactory and has been commented a lot because practice by itself is not evidence of the existence of a custom but the custom is the source to be applied. The norm should be applied. Therefore it would be more correctly if Article 38 was phrased as ‘International Custom as evidence by a general practice accepted as law’.

The emergence of the customary law is based on certain principles and these principles derive from the practice of states. These principles are governing the Customary Law and reflect the base from which customary law emerges. There are certain exceptions to the customary law like the local custom or the persistence objector that can be argued to allow States to escape from their obligations contrary to the uniform implementation of Customary law.

The General Principles Of Law

The third source of international law is the general principles that were developed in order to provide a solution in cases where treaties and custom provided no guidance. General principles of law fill the gaps that are left from International conventions and customary law. General principles of law derive from principles which are based on the legal system of individual States. General principles of law derive only by Civil law or Common law only from the general principles of law recognized by the civilized nations.

International law is not as complete and highly developed as municipal law. International law is still developing and in many cases the general principles of law were used. In the case of Chorzow Factory (PCIJ 1928) the general principles of Law applied in this case.

“A violation of an engagement gives right to a duty to make reparation”. In the Corfu Channel (ICJ 1949) the value of circumstances element (ICJ) borrowed elements from municipal law and used them to International law. And in the case of Temple (ICJ 1962) which was concerning a dispute between Thailand and Cambodia about a temple the ICJ used the principle of Estoppel. Thailand failed since 1908 to claim the temple and therefore was estopped from claming it.

Facts flowing from wrongful conduct cannot determine the law. In the case of Cyprus V Turkey. Turkey cannot made there wrongful invasion to Cyprus into a general principle of law. General principles of municipal law have been borrowed by international law in order to assist the ICJ into reclaiming a decision.

The extent to which general principles of law can be incorporated to the International law to which Article 38(1) of the Statute of the ICJ refers is unclear and controversial but may include such legal principles that are common to a large of systems of municipal law. The Article 38(1) provides direction to the Court and as a safe net fills any gap in the law left by the treaties or the customary law and prevent the situation where there is no applicable law by using the general principles.

Judicial Decisions

The fourth source of international law is the judicial decisions. Judicial decisions are subsidiary means for the determination of rules of law. International courts are not obliged to follow previous decisions but almost always take previous decisions into account. Judicial decisions are useful source of information as what international law is because of the prevailing notion of equality before the law.

International courts are permanent courts meaning the International Courts of Justice. That is a court of UN it derives from article 38(1) it tries disputes between States. It has advisory jurisdiction Countries States which have international identity) and wears disputes against States only. And the International Criminal Court that deals with war crimes, genocide crimes and crimes against humanity. It tries only individuals and must be requested from a State.

Ad Hoc Courts (temporary Courts) are created were there is need such as in the cases of Rwanda – Tanzania, Yougoslavia (1991), Sierra lione, Cabotia, etc. All these ad hoc courts were the inspiration for the ICC. Judgments are binding to the dispute States.

The last source of the International Law is the different Scholars that help to the development of international law. The scholars help to direct the development of international law but they do not create the law.


The International law must develop continuously since it must coincide with the pace of the development of the world. The international law was mostly developed in order to regulate the interactions of the states. The twentieth century has been a great emphasis on international co-operation, whereby states work together rather than individual.

The technological developments, the International Organizations (e.g. UN) necessitate even more the need for the development of the international law. The five sources of the international law derive form a statute that was created many years ago after the second world war.

It can be argued that the International law is a very complicated field of study due to the peculiarity of each source of international law, the legal rules that emerge may derive from a combination of all the sources together and not only from one source. Therefore, in many instances it is difficult to identify the base from which they emerge.

In addition to these, the drafting of the PCIJ statute Article 38 was complete and exhaustive. It is very difficult for a new source to come into existence subsequently.

According to Evans, M. ‘the quest of a tertiary rule, one that lays down how the secondary rules might be created or modified for a ‘fundamental norm’ underlying all international law has proved to be vain’.

The modification of the secondary rules that enumerate the sources of international law is a necessity because since the Treaty of Westphalia the international society has changed drastically.

According to Evans, M. some additional sources or quasi- sources have been suggested to become sources of international law such as the unilateral acts which are relevant to international law. Unilateral acts of States in the structure of the international law were doubtful or marginal until the decision of the International Court in 1974 in the Nuclear tests case where the Court held that France had assumed legal binding obligations through unilateral obligations, made to the world at large. Unilateral declarations may have the effect of creating legal obligations.

Equity could possibly become one of the new sources of international law. Innovations of equity have played an increasing part in international legal discourse of recent years.

(Barcelona Traction, Light and Power co case). Equity is probably best regarded, in words applied by the International Court to the comparable principle of good faith, as one of the basic principles governing the creation and performance of legal obligations, but ‘not in itself a source of obligation where none would otherwise exist’.

Another probable source of the international law might be the resolutions of the International Organisations that enjoy almost universal membership. Many Resolutions of the UN General assembly are convenient sources of international law since they represent a huge amount of countries (members). These resolutions could have been awarded with the title as a formal source of law. (Case of the Legality of The Threat or Use of Nuclear Weapons).

Another source of law could be the category of the peremptory legal norms from which no derogation is allowed by the states. It is widely recognised by the majority of the States that a ius cogens norm derives from the importance of the content of the norm to the international community. Therefore these norms could probably have the status as a formal source of the International Law.

Bibliography – References

Evans, M. (2003), International Law, New York: Oxford University Press.

Charlesworth, H. Falk, R. & Weston, B. (1996), International Law and world order a problem oriented coursebook, USA: West Group.

Harris, Dj. (2004), Cases and materials on International Law, London: Sweet & Maxwell.

Higgins, R. (1994), International Law and how we use it, New York: Oxford University Press.

Wallace, R. (1997), International Law, London: Sweet & Maxwell


Lecture notes

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