ULUSLARARASI KAMU HUKUKU I

A formal source is that from which a rule of law derives its force and validity. The material sources, on the other hand, are those from which is derived the matter, not the validity of the law. From formal sources, the law derives its authority or sanction. The procedures or methods by which rules become legally binding are formal sources of law.

The internationally accepted classification of sources of international law is formulated in Article 38 of the Statute of the International Court of Justice. These sources are:

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 the teachings of the
most highly qualified publicists of the various
nations, as subsidiary means for the
determination of rules of law

Ex aequo et bono means what is just and fair or according to equity and good conscience. Something to be decided ex aequo et bono is something that is to be decided by principles of what is fair and just. A decision-maker who is authorized to decide ex aequo et bono is not bound by legal rules but may take account of what is just and fair (USLegal.com).

Whereas treaties, custom, and general principles of law are the main sources ofinternational law, judicial decisions and juristic
work on international law fall into the category of subsidiary sources. Custom may be treated as a source of law if it manifests the attributes of antiquity, certainty, continuity, consistency, and uniformity.

Opinio juris sive necessitatis means “an opinion of law or necessity.” It is the belief that an action was carried out because it was a legal obligation. This term is frequently used in legal proceedings as a defense in a case (USLegal).

A treaty is contractual in nature, its being a source of law is debatable, as it primarily creates obligations for the parties thereto. It does not ipso facto (by that very fact) bind the non-signatories except the treaties that are “constitutive” or “dispositive” in nature. In other words, treaties establish a special régime, international boundaries, or an international institution. They create rights and obligations for third parties.

Non-liquet means “it is not clear.” In law, a non liquet is a situation where there is no applicable law. It refers to a situation in which a competent court or tribunal fails to decide the merits of a case for the absence of suitable law, the vagueness or ambiguity of rules, inconsistencies in law, or the injustice of the legal consequences.

Res judicata [Latin; a matter that has been decided]: The principle that when a matter has been finally adjudicated upon by a court of
competent jurisdiction it may not be reopened or challenged by the original parties or their successors in interest. It is also known as action estoppel (Martin, 2003: 430).

When the State practice is either ambiguous, non-existent,
sparse, or contradictory, courts get involved in determining the rules of law in order to decide a legal issue and in this process they create new rules. Decisions rendered by the courts are of immense value; and in those cases where there is no preexisting
rule, these decisions become a direct source of law.

Amiable compositeur under international law refers to an unbiased third party, who suggests solution to a dispute between countries. An amiable compositeur acts as a conciliator or a mediator rather than a decision-maker in a dispute. An amiable compositeur is also not bound to apply strict rules of civil procedure and substantive law (USLegal.com).

From formal sources, the law derives its authority or sanction; and from material sources, the law derives its content or subject matter. Thus, a rule will be legally binding if it fulfils the requirements of a custom, which is a formal source of international law.

In the case of the law-creating process, the emphasis lies on the forms by which
any particular rule of international law is created. This is being done through the law-determining agencies, (those stated in sub-paragraph d), that verify an alleged rule (Schwarzenberger, 1967). These agencies have been termed as subsidiary means.

In order to avoid a situation of non-lique, (i.e., no law exists or law is silent on the issue), Article 38 paragraph (2) empowers the Court “to decide a case ex aequo et bono if the parties agree thereto”.

 Ex aequo et bono means what is just and fair or according to equity and good conscience. Something to be decided ex aequo et bono is something that is to be decided by principles of what is fair and just. A decision-maker who is authorized to decide ex aequo et bono is not bound by legal rules but may take account of what is just and fair.

Custom is a habitual course of conduct or general practice accepted as law. Custom evolves after a long historical process culminating in its recognition by the community. Custom may be treated as a source of law if it manifests the attributes of antiquity, certainty, continuity, consistency, and uniformity.

Acquiescence, however, cannot be established unless a State has actual or constructive knowledge of the claim being made.

For example, in the satellite launching, the acquiescence of all States
has resulted in the change of airspace law. Further, it is not necessary that a new rule should emerge only out of compromises or mutual tolerances; it may also be evolved by consensus, rather in a short span of period, such as in the case of law relating to outer space.

State interactions with other nations in the form of diplomatic correspondence, press releases, bilateral treaties, memorandums of understanding,acts or declarations by statesmen etc. constitute evidence of practices of States followed in the sphere of international relations. A uniform practice among nations on a particular aspect leads to the formation of a customary rule. Rules may also evolve as a result of positive statements, interaction of rival claims, or the acquiescence in or tolerance of the other’s claim.

The existence of a practice uniformly followed by all States may be of some evidence that a custom does exist. Nevertheless, what is required for the existence of a custom is the concurrence and not mere parallelism of such practices that may be indicative of the general recognition of a broad principle of law. The Scotia case (the USA vs. UK, 1871) is in point.

Treaties (conventions) constitute the most important source of modern international law. Addressing the needs of modern international society and keeping pace with the changes in international relations make it imperative to develop international rules.

This can be accomplished only through concluding treaties among nation States and not by the slow process of creating customary law.

Non-liquet means “it is not clear.” In law, a non liquet is a situation where there is no applicable law. It refers to a situation in which a competent court or tribunal fails to decide the merits of a case for the absence of suitable law, the vagueness or ambiguity of rules, inconsistencies in law, or the injustice of the legal consequences.

In theory, judicial decisions do not constitute a formal source of law; in practice, however, they play a substantial role in the development of international law.

When the State practice is either ambiguous, non-existent, sparse, or contradictory, courts get involved in determining the rules of law in order to decide a legal issue and in this process they create new rules. Decisions rendered by the courts are of immense value; and in those cases where there is no preexisting rule, these decisions become a direct source of law.