Primary Sources of Public International Law

International Law has been variously defined by different international jurists.

(1) As defined by Oppenheim: “Law of Nations or International Law is the name for the body of customary and treaty rules which are considered legally binding by civilized states in their intercourse with each other.
(2) As stated by G.J. Starke: “International law may be defined as that body of law which is composed for its greater part of the principles and rules of conduct which states feel themselves bound to observe, and, therefore, do commonly observe in their relations with each other.”  

Source of Law connotes the origins from which particular positive laws derive their authority and coercive force; such as, customs, usages, constitutions, statutes, treaties. In another sense, the authoritative or reliable works, records, documents, edicts, etc., to which we are to look for an understanding of what constitutes the law. The same is the concept of the sources of international law.

The Statute of the International Court of Justice The relevant provisions of this statute are as follows:

• 1. Article 38 (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 customs, 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 the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of laws. 

• 2. This provision shall not prejudice the power of the Court to decide a case ex aequo et bono,(what is right and good), if the parties agree thereto. Article 59. The decision of the court has no binding force except between the parties and in respect of that particular case.

(a) Definition: 

International treaty is an agreement, league or contract between two or mere nations or sovereigns formerly signed by commissioners properly authorized, and solemnly ratified by the several sovereigns or the supreme power of each state. It is not only a law but also a contract between two nations and must, 1f possible, be so construed , as to give full force and effect to all its parts. 

(b) Foundation: 

International lawyers use the phrase “Pacta Sunt Servanda ” to express the fundamental principle that agreements even between sovereign states, are to be respected. 

(c) Significance: 

International treaties are not only a principal source of international legal rules but are also themselves the subject of a considerable body of international law. The law of treaties serves much the same function in the international law as the law of contracts does in municipal law. 

(d) Treaty takes priority: 

There is no doubt about the fact that treaty stipulations override rules of international customary law which are incompatible with them. This proposition received approbation in the case of S S. Wimbledon (1923), where the permanent Court of international Justice held that treaty law takes priority over international customary law. 

Treaties may be divided into four kinds, which stand as follows

(i) Law-Making Treaty It lays down general rules binding on the states or enunciates new general rules for the guidance of the states in future or for their future international conducts.

(ii) Treaty Contracts  It deals with a special matter between the contracting states only.

(iii) Bilateral Treaty  It is a treaty which comprises only two parties and thus, is binding only on them. This treaty, usually, constitutes a treaty contract

(iv) Multilateral Treaty If there are more than two parties in a treaty it is called multilateral treaty Usually, such treaty is also referred as a law making treaty, if it contains a considerable number of states. 

Some Alternative names for treaty: 

Treaties are known by a variety of differing names;  

Conventions, International agreements, Pacts, General Acts, Final Acts, Acts, Concordat, Protocol, Charters, Statutes, Declarations and Covenants. 

All these terms refer to a similar transaction, the creation of written agreement whereby the states participating bind themselves legally to act in a particular way or to set up particular relations between themselves. 

Following are some instances of the important international treaties: 

• i. Treaty of Westphalia (1648) 
• ii. Paris (1815) and Versailles (1899) Charters 
• iii. Geneva Conventions of 1864, 1906, 1929 and 1949  
• iv. Hague Conventions of 1899 and 1907 
• v. Covenant of League Of Nations ( 1920) 
• vi. Charter of United Nations, 1945 
• vii. Rome Treaty 1998, 2002 

Term ‘Custom’ generally implies to habitual practice or course of action that characteristically is repeated in like circumstances. 

(b) Custom and Usage: 

In order to understand custom it is necessary to know the meaning of the word “Usage". As pertinently explained by J.G.Starke “a usage is twilight stage of custom. “Usage is a repetition of acts, and thus, differs from “custom” in that the latter is the law or general rule which arises from such repetition, while there may be usage without custom, there cannot be a custom without a usage accompanying or proceeding it. 

(c) Significance: 

Article 38 (b) of the Statue of International Court of Justice recognizes international custom, as evidence of general practice accepted as law, as one of the sources of international law. For most modern international lawyers, customary international law is alongside treaty law, one of the two central forms of international  law. 

Following elements constitute a valid international custom: 

(i) Duration: 

No particular duration is required nor does international court emphasize the time element as such in its practice. Provided the consistency and generality of a practice are proved. 

(ii) Uniformity and Consistency: 

Substantial uniformity and consistency of practice is required for a valid custom. 

(iii) Generality of the Practice  

As rightly remarked by Brownli, certainly universality is not required but the real problem is to determine the value of abstention from protest a substantial number of states in face of a practice followed by sonic others.”  

(iv) Opinio Juris et necessitates: 

The statute of the International Court refers to a general practice accepted as law, briefly speaks of recognition by states of a certain practice “as obligatory” and Hudson requires a “conception that the practice is required by, or consistent with, prevailing international law.” Some writers do not consider this psychological element to be a requirement for the formation of a custom, but it is, in fact, a necessary ingredient. 

(e) Judicial Application of Custom: 

According to GJ. Starke, “Both national and international courts play an important role in the application of custom. Often it is claimed by one of the parties before the court that a certain rule of customary international law exists. The Court must then investigate whether or not the rule invoked before it is validly established rule of international custom and in the course of this inquiry it examines all possible materials. 

As enumerated by Brownli, “The material sources of custom are very numerous and include the following.

• a. Diplomatic correspondence.  
• b. Policy statements. 
• c. Press releases. 
• d. The opinions of official legal advisers.  
• e. Official manuals on legal questions, e.g., manuals of military law, executive decisions and practices, order to naval forces etc. 
• f. Comments by governments on drafts produced by the International Law Commission. 
• g. State legislation.  
• h. International and national judicial decisions.  
• i. Recitals in treaties and other international instruments.  
• j. A pattern of treaties in the same form. 
• k. The practice of international organs.  
• l. Resolutions relating to legal questions in the United Nations General Assembly. 

General Principles of  Law Recognized By Civilized Nations

Article 38 of the Statute of International Court of Justice lists ‘the general principles of law recognized by civilised states as the third source of international law, This source helps international law to adopt itself in accordance with the changing circumstances.

Lord McNair has pertinently written, “Article 38, paragraph 1(c) of the Statute of International Court of Justice.... places on record one of the main sources of the rules of public international law. Indeed, it describes the inexhaustible reservoir of legal principles from which the tribunals can enrich and develop public international law.

Examples of General Principles of  Law

Final Analysis on  General Principles of  Law:

It may be concluded that by recognizing general principles of law recognized by civilised states, dynamism of international law and the creative function of the International Court have been recognized.

Judicial Decisions as Source of International law

The significance of judicial decisions as an important material source of international law can be understood by the following heads:

In the modern period, the International Court of Justice is the main international Judicial tribunal. It was established as a successor of the permanent Court of International Justice. It is to be noted that the decision of the International Court of Justice does not create a binding rule of international law, under Article 59 of the Statute of the International Court of Justice. This Court does not follow the doctrine of Judicial precedents just as the municipal courts. However, it clarifies the rule of international law on a particular point or matter. According to Article 3(1)(d), subject to the provisions of the Article 59, judicial decisions are “subsidiary means for the determination of rules of law.” Therefore, judicial decisions are not a direct source of international law, but subsidiary and indirect.

As rightly remarked by Ian Brownlie, “The literature of the law contains frequent reference to decisions of arbitral tribunals. The equality of arbitral tribunals has varied considerably, but there have been a number of awards which contain notable contributions to the development of the law by eminent jurists sitting as arbitrators, umpires or commissioners.”

Several decisions of this court have involved issues of general importance.

Article 38(1)(d) of the Statute of the International Court of Justice is not confined to international decisions and the decisions of national tribunals have evidential value. Some decisions provide indirect evidence of the practice of the state of the forum on the question involved (stated by judges Finlay and Moore); others involve a free investigation of the point of the law and consideration of available sources and may result in a careful exposition of the law.

Hall, Oppenheim, Moore, Hyde, McNair, and other Writers from common law jurisdictions make frequent reference to municipal decisions and such use is universal in monographs from this source. French, German and Italian Jurists tend to use fewer case references, while Russian jurists are even more sparing. However, the value of these decisions varies considerably, and many present a narrow national outlook or rest on a very inadequate use of the sources. 

Tribunals set up by agreement between a number of states for some ad hoc purpose, may produce valuable pronouncements on delicate issues, much depending on the status of the tribunals, its members and the conditions under which it does its work, For example, the judgement of the International Military Tribunal for the trial of German major war criminals and decisions of the Iran-United States Claims Tribunal contain a number of significant findings on issues of law.

The Supreme Court of the United States, The Swiss Federal Court, and the Staatsgerichtshof of the Weimar Republic have had occasion to decide disputes between members of the Federal communities involved on the basis of doctrines of international law. The practice of the first of these is of importance in view of the fact that the United States has its origin in a union of independent states and this gives an international element to its internal relations.

Pleadings before the international court contain valuable collections of material and, at the least, have value as comprehensive statements of the opinions of particular states on legal questions. 

The Writings of Publicists (Juristic Works) as source of international law

Article 38 of the Statute of the International Court of Justice directs the Court to apply the teachings of the most highly qualified publicists of the various nations as subsidiary means for the determination of the rules of law. This provision emphasises the evidentiary value of jurists' works. As remarked by J.G. Starke, “Juristic works are not an independent source of international law although sometimes juristic opinion does lead to the formation of international law.” 

EX AEQUO ET BONO as Source of international law

After enumerating the sources of international law in Article 38(1), Article 38(2) of the World Statute qualifies Article 38(1) by providing: This provision shall not prejudice the power of the court to decide a case ex aequo et bono, if parties agree thereto “Ex aequo et bono” is a phrase derived from the civil law, meaning, in justice and fairness; according to what is just and good, according to equity and conscience.

“In a case where the parties are agreed that it may decide ex acquo et bono the provision in the statute would seem to enable the court to go outside the realm of law for reaching its decision. It relieves the court from the necessity of deciding according to law.

Other Sources Of International Law As Pointed Out By Eminent Writers

Decisions And Determinations Of The Organs Of International Institutions

J.G. Starke, Ian Brownlie and several other writers lay great emphasis on the decisions and determinations of the organs of international institutions as sources of international law such as the United Nations.

International Comity:

Comity, simply means courtesy, complacence, respect; a willingness to grant a privilege, not as a matter of right but out of difference and goodwill. In general, the principle of “Comity” is that courts of one state or jurisdiction will give effect to laws and judicial decisions of another state or jurisdiction, not as a matter of obligation but out of difference and mutual respect. According to Prof. Oppenheim, international comity has helped in the development of international law. According to Article 38 of the Vienna Convention on Diplomatic Relations, 1961, international comity, comitas gentium, is a species of accommodation not unrelated to morality but to equity distinguished from it nevertheless. Neighbourhood, mutual respect and the friendly waiver of technicalities are involved, and the practice is exemplified by the exemption of diplomatic envoys from customs duties.

State Papers

State Guidance For Their Officers

Peremptory Principles Or Norms As Source of international law ;

Jus Cogen is the name of the body of peremptory principles or norms from which no derogation is permitted, and which may therefore operate to invalidate a treaty or agreement between states to the extent of the inconsistency with any of such principles or norms. As per Article 53 of the Vienna Convention on the law of treaties, 1969, it is an additional feature of a norm of jus cogen that it can be modified only by a subsequent norm of general international law having the same character, although on this Article jus cogen is defined merely for the purposes of the convention. Thus, jus cogen, sometimes, serves as an effective source of international law. 

Equity in Judgments And Advisory Opinions Of The International Court

Considerations Of Humanity

“Until a more complete code of the laws of war can be drawn up, the High Contracting Parties deem it expedient to declare that, in cases, not covered by the rules adopted by them, the inhabitants and the belligerents remain under the protection and governance of the principles of the law of nations, derived from the usage established among civilised people, from the laws of humanity and from the dictates of the public conscience.” 

Considerations of humanity have played an important role in the development of international law. In the modern period, the provisions of the United Nations Charter concerning the protection of human rights and fundamental freedom, and reference to the “principles” of the charter, have been used as a more concrete basis for considerations of humanity, for example in matters of racial discrimination. (Quoted by Ian Brownlie) 

Legitimate Interest

In particular contexts, rules of law may depend on criteria of good faith, reasonableness, and the like and legitimate interest, including economic interests, may then be taken into account. However, legitimate interests may play a role in creating exceptions to existing rules and bringing about the progressive development of international law. Recognition of legitimate interest explains the extent of acquiescence in face of claims to the continental shelf and fishing zones.

Reason