Introduction
The term “sources of Public International Law” is used to mean two things: first, the actual materials determining the rules applicable to a given international situation (the material sources), and second, the legal methods creating rules of general application (the formal sources). However, because it is difficult to maintain this distinction, the two meanings are used interchangeably.
Article 38 of the Statute of the International Court of Justice (ICJ) states the following:
1. The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:
a- international conventions, whether general or particular, establishing rules expressly recognized by the contesting states;
b- international custom, as evidence of a general practice accepted as law;
c- the general principles of law recognized by civilized nations;
d- subject to the provisions of Article 59, judicial decisions and teaching of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.
2. This provision shall not prejudice the power of the Court to decide a case ex aequo et bono, if the parties agree thereto.
This Article lists the traditional sources of Public International Law, the actual legal materials that the ICJ has to apply to international disputes. According to this Article, these sources are of two types: the primary sources that are represented by the international conventions, international custom and general principles of law; and the subsidiary sources that are represented by the decisions of courts and the opinions of legal scholars. Moreover, this Article lists “ex aequo et bono” (equity) as an alternative source of Public International Law applied by the Court if the parties agree thereto. However, in addition to these traditional sources, there are contemporary sources, such as the acts of the international organizations.
Thus, the sources of the contemporary Public International Law can be classified into seven:
1- International customs;
2- Treaties;
3- General principles of law;
4- Judicial decisions;
5- Opinions of legal scholars;
6- Ex aequo et bono (Equity);
7- Acts of international organizations.
In the following sections, these sources are discussed.
International Customs
Article 38 of the Statute of the ICJ refers to an international custom as evidence of a general practice accepted as law. This definition comprises of two elements: a general practice and its acceptance as law. These two elements are necessary for the formation of customary international law. The first element, the behavioural or objective element, requires a recurring consistent action or lack of action by States, which is indicated by such activities as official statements or conducts, legislative or administrative action, court decisions and diplomatic behaviours or correspondence. The second element (the psychological or subjective element) entails the conviction that in similar case such a practice is required or permitted by international law. In this sense, international customs may be defined as practices or usages which have been observed by a large number of States over a lengthy period of time and considered by them to be legally obligatory, i.e., being a law.
Notably, the terms “custom” and “usage” are often used interchangeably. Strictly speaking, there is a clear technical distinction between the two. Usage is an international habit of action that has not received full attestation and does not reflect a legal obligation; an example of a usage is the salute at sea. Usages may be conflicting; custom must be unified and consistent. A usage to become a customary rule of law, it must fulfill two conditions: acceptance or recognition by a large number of States and repetition over a lengthy period of time. A custom has a definite obligation attached to it. Failure to follow custom results in State responsibility, and consequently entails the possibility of punishment (sanction) or of retaliation against that State.
International custom, as Article 38 indicates, is one of the primary sources of International Law which the ICJ shall apply. In fact, international customs constituted the bulk of the rules of International Law. Historically, custom had played a great role in the formation of the rules of International Law. However, since the beginning of the Twentieth Century, this role has been decreased in favor of the law-making treaties.
Treaties
The term “treaty” is used as a generic term embracing all kinds of international agreements which are known by a variety of different names such as, conventions, pacts, general acts, charters, statutes, declarations, covenants, protocol, as well as, the name agreements itself. A treaty may be defined as an international agreement concluded between States in written form and governed by International Law.
Article 38 of the Statute of ICJ indicates that international conventions (treaties), whether general or particular, establishing rules expressly recognized by the contesting states should be applied by the Court to the disputes submitted to it. Although this Article divided treaties into two kinds, general treaties and particular treaties; it is only the first kind, the general treaties or the so called the law-making treaties, which intended to have a universal and general application, constitute a primary source of International Law.
The particular treaties or the so called treaty-contracts are not directly a source of International Law since their application is limited only to the contracting parties which are two or small number of States, and they deal with limited affairs . This kind of treaties does not create new rules of Public International Law, but at best, only new rules of particular or regional application. However, as a substantial number of States accept and recognize such new rules formulated in this kind of treaties as obligatory, these rules will become part of the Public International Law. Examples of such treaties are bilateral treaties on commercial, and friendship relations.
The law-making treaties constitute a primary source of International Law. Since the middle of the Nineteenth Century, there has been an astonishing development of law-making treaties. The rapid expansion of this kind of treaties has been due to the inadequacy of customs in meeting the urgent demands arose from the changes which have been transforming the whole structure of international life. Law-making treaties have been concluded to regulate almost every aspect concerning the international community. Examples of important treaties are: the Charter of the United Nations, the four Geneva Conventions of 1949, the Vienna Convention on Diplomatic Relations of 1961, the International Covenant on Civil and Political Rights of 1966 and the Convention on the Law of the Sea of 1982.
In contrast with the process of creating law through custom, treaties are a more modern, more deliberate and speedy method. They are of growing importance in International Law. Their role in the formation of new rules of International Law increases day after day. Today, the law-making treaties are considered the most important primary source of Public International Law.
General Principles of Law
Article 38 of the Statute of the ICJ refers to “the general principles of law recognized by civilized nations” (all nations are now considered as civilized) as a primary source of International Law. This source is listed the third after international conventions and international customs. The Court shall apply the general principles of law in cases where treaties and customs provide no rules to be applied.
Notably, there is no agreement on what the term “general principles of law” means. Some say it means general principles of international law; others say it means general principles of national law. Actually, there is no reason why it should not mean both; the greater expansion in the meaning of this term, the greater chance of finding rules to fill the gaps in treaty law and customary law. Indeed, international tribunals had applied general principles of law in both senses for many years before the Permanent Court of International Justice was established in 1920.
Nevertheless, there are various opinions as to the origin of the general principles of law. Some regard them as being originated from the Natural Law which underlies the system of International Law and constitutes the criteria for testing the validity of the positive rules. Others regard them as stemmed from the national legal systems (Positive Law) and have been transplanted to the international level by recognition.
Whatever the meaning of the term “general principles of law” and the origin of these principles, these principles are considered to be at the foundation of any legal system, including International Law. Actually, there is an agreement that the general principles of law do constitute a separate source of International Law. Examples of general principles of law are the principles of consent, equality, administration of justice, good faith, reciprocity, forbidding abuse of right andres judicata.
Judicial Decisions
Article 38 of the Statute of the ICJ directs the Court to apply judicial decisions as subsidiary means for the determination of rules of law. This direction is made subject to the provisions of Article 59, which states that “the decision of the Court has no binding force except between the parties and in respect of that particular case.” The provision of Article 59 of the Statute of the ICJ is understood to mean that the Court is not obliged to follow previous decisions. So while, as Article 59 ascertained, the doctrine of precedent as it is known in the Common Law, whereby the decisions of certain courts must be followed by other courts, does not exist in International Law, it is still that the decisions of the international courts (PCIJ and ICJ) are quoted as authoritative decisions, and international courts have always strived to follow their previous decisions to insert certainty and uniformity within their judicial process, or at least, they have had to take previous decisions into account.
The judge of the ICJ sometimes does a little more than merely determine a law; he may establish a law. This has occurred in many instances: the Anglo-Norwegian Fisheries case of 1951, which stated the criteria for the recognition of baseline from which to measure the territorial sea; and the Reparations case of 1949, which established the legal personality of international organizations.
The PCIJ, during its existence, gave a large number of decisions and advisory opinions on matters of international concern, thereby developing International Law. The ICJ, the successor of the PCIJ, has been doing the same.
As the term “judicial decisions” referred to by Article 38 also encompasses decisions (awards) of international arbitral courts (tribunals) and the decisions of national courts, these decisions have been playing a role in the development of International Law.
There have been many international arbitral tribunals, such as the Permanent Court of Arbitration and the various mixed-claimed tribunals, including the British-American Mixed Claims Tribunal and the Iran-US claims Tribunal. Although these tribunals differ from the international courts in some ways, many of their decisions have been extremely significant in the development of International Law.
The decisions of national courts of various nations have played a role the development of International Law, particularly the international customary law. These Decisions help to form international customs. They show what the national courts have accepted as international law and how the International Law, in the given case, is understood in that country. Examples of such rules of law developed by, or derived from the uniform decisions of national courts are certain rules of extradition law, the rules related to State recognition, and the rules of diplomatic immunity.
One may finally say that judicial decisions, whether international or national, have played an important part in the development of International Law. The international customary law has largely developed from case to case, and a large number of cases have been submitted to international as well as national courts of various nations.
Writings of legal scholars
Article 38 of the Statute of the ICJ includes as a subsidiary means for the determination of rules of law, “the teachings of the most qualified publicists of the various nations”. The term “teachings of publicists” means “writings”, “opinions” or “works” of legal scholars, jurists or writers.
This Article emphasizes the evidentiary value of writings of the legal scholars. The primary function of these writings is to provide reliable evidence of the law. Writers on International Law cannot make the law; their works are to elucidate and ascertain the principles and rules of International Law. To be binding, the rules and principles must have received the consent, whether express or implied of States, who are to be bound by it.
Historically, the writers on International Law such as Gentili, Grotius, Pufendorf and Vattel were a primary factor in the evolution of the modern International Law; they were the supreme legal authorities of the Sixteenth to Eighteenth Centuries. They determined the scope, form and content of International Law. However, the importance of legal writings began to decline as a result of the emphasis on the state sovereignty; treaties and customs assumed the dominant position in the exposition and development of International Law.
Nevertheless, like judicial decisions, the opinions of legal scholars can provide evidence of the existence of customary law and can help in developing new rules of law.
The opinions of legal scholars are used widely. Arbitral tribunals and national courts make extensive use of the writings of jurists. However, the International Court of Justice makes little use of jurisprudence, and judgments contain few references; this is, primarily, because of the willingness of the Court to avoid a somewhat undesirable selection of citations. However, many references to writers are found in the pleadings before the Court.
Ex aequo et bono (Equity)
Article 38 of the Statute of the ICJ lists ex aequo et bono as an alternative basis for a decision by the Court in place of the normally employed legal rules. The Court can decide a case submitted to it ex aequo et bono (in justice and fairness)only if the parties agree thereto. Ex aequo et bono is somewhat analogous to but not exactly the same as the Common Law concept of equity. It is broader than equity and gives the Court greater power than the latter. It allows the Court to decide a case on considerations other than legal rules, or even in contrary to these rules, if it sensed that justice can be served thereby. Thus the term “ex aequo et bono”means “justice and fairness” or “equity”.
Neither the International Court of Justice nor its predecessor, the Permanent Court of International Justice, has been called upon to decide a case ex aequo et bono, although principles of equity have been applied by these courts in some cases. The ICJ in the North Sea Continental cases (1969) directed the delimination between the parties (West Germany, Holland and Denmark) “in accordance with equitable principles”. The PCIJ in the Diversion of Water from the MeuseRiver case (1937) applied principles of equity after considering them as part of the International Law which it should apply. Moreover, international arbitral tribunals have resorted to the principles of equity in several cases.
Despite the application of the principle of equity by international courts, the existence of “equity” as a separate and distinct source of law is highly controversial. Some regard equity as a source of International Law, and apply it as distinguished from law; however, they often appeal to natural law in order to strengthen their arguments. Thus to them the three terms “equity”, “justice” and “natural law” tend to merge into one another. During the Sixteenth and Seventeenth Centuries natural law was a major source of International Law. In the Nineteenth and Twentieth Centuries arbitrators have often been authorized to apply justice and equity as well as International Law; such authorization were more common before 1920 than they are today.
Other scholars do not recognize equity as a separate and distinct source of law; they regard the principles of equity as part of the general principles of law that are common to all national legal systems.
Whatever the position may be, it is doubtful whether equity form a source of international law. It cannot be assumed that a judge uses equity as a source of law every time he describes a rule as equitable or just. Strictly, “equity” cannot be a source of law; yet it may play an important role in supplementing the law or may appear as a part of judicial reasoning. A judge or arbitrator can always use equity to interpret or fill gaps in the law, even when he has not been expressly authorized to do so. But he may not give a decision ex aequo et bono unless he has been expressly authorized to do so.
Acts of International Organizations
The growth of international organizations since the First World War has been accompanied by suggestions that the acts of these organizations should be recognized as a source of International Law. The question involved hereto is whether the decisions of the organs of these organizations can be regarded as a separate source of International Law.
Decisions of the organs of international organizations may be binding or non-binding. An organ may be authorized to take decisions which are binding on member states; only these binding decisions are regarded as a source of the International Law. The only clear example of binding decisions is the resolutions which the Security Council of the United Nations are authorized to take under Chapter Seven (VII) of the Charter of the United Nations dealing with actions related to threats to the peace, breaches of the peace, and acts of aggression.
However, there is a controversy concerns the non-binding decisions of the organs of the international organizations. Since almost all the organs of the international organizations are composed of representatives of member states and their acts are merely the acts of the states represented in these organs, they would probably constitute an evidence of customary law because they reflect the views of the state voting for them. The obvious examples of such type of acts are the resolutions and declarations of the General Assembly of the United Nations. When the vast majority of States, in the General Assembly, consistently vote for resolutions and declarations on a certain topic, a State practice will be established and a binding rule of customary International Law will emerge. Thus, these resolutions and declarations will constitute an evidence of the existence of customary International Law. Examples of such resolutions and declarations regarded as examples of State Practice which have led to binding rules of customary International Law are: “the Resolution on Prohibition of the Use of Nuclear Weapons for War Purposes”, “the Declaration on Granting of Independence to Colonial Countries and Peoples”, “the Declaration on Permanent Sovereignty over Natural Resources” and “the Declaration of Legal Principles Governing Activities of States in the Exploration and Use of Outer Space”.
Resolutions and declarations of the General Assembly may also provide a basis for the progressive development of the International Law and the speedy adaptation of customary law to the conditions of modern life. Moreover, in some instances, a resolution or declaration may have direct legal effects as an authoritative interpretation and application of the principles stated in the Charter of the United Nations.
