Sources of International Law | Public International Law - CLAT PG PDF Download

Introduction

Sources of international law are the materials and processes out of which the rules and principles regulating the international personalities are developed. According to Lawrence and Oppenheim there is only one source of International law and that is the consent of nation. Brierly considers customs and reasons as the main sources of international law.

Article 38(1) of the statute of the International Court of Justice is widely recognized as the most authoritative statement as to the sources of International law. On the basis of Article 38 of ICJ Statute five distinct sources can be identified. They are International conventions/treaties, International customs, General principles of law, Judicial decisions and writings of the publicists and Reason and equity.

International Conventions or Treaties

Law-Making Treaties

• Law-making treaties are agreements entered into by a large number of states and serve as a direct source of international law. These treaties are binding and can be further categorized into:
• Treaties establishing Universal International Law: These treaties are signed by a majority of states and establish rules of universal applicability. An example is the United Nations Charter.
• Treaties establishing General Principles: These treaties are signed by many countries and outline general principles of international law, such as the Geneva Convention on the Law of the Sea and the Vienna Convention on Diplomatic Relations (1961).

Treaty Contracts

• Treaty contracts are agreements between two or more states, with binding provisions only applicable to the parties involved. While these treaties also contribute to international law, they do so by helping develop customary rules.
• Critics argue that the classification of treaties is misleading because both types create binding rules. In law-making treaties, a large number of states are involved, and the obligations are agreed upon voluntarily. Treaties establish rules and principles of international law based on the common consent of states. In the absence of a law-making authority, international conventions play a crucial role.
• International conventions go beyond customary rules. Treaty stipulations take precedence over conflicting rules of international customary law, as established in the case of S.S. Wimbledon (1923) by the Permanent Court of International Justice. This court ruled that treaty law supersedes international customary law.
• While conventional and customary rules are not the only sources of international law, they are essential in filling the gap due to the lack of a law-making authority.

Customs

• Custom is the older and original Source of International Law. It is as such Second Important source of International Law. International Law Custom may mean a kind of qualified practice, by the existence of a corresponding legal obligation to act according to this practice, hence by the existence of the corresponding rule of International law. The customs are evolved through the practices of and usages of the nation and their recognition by the community of nations. Customary rules are those rules which are practiced by most of the States by way of habit for a pretty long time.
• International custom has developed by spontaneous practice and reflects a deeply felt community of law. Its rules are regarded as possessing density and stability and it is the repository of the general or common law of the nations.

The General Principles of Law

• The General Principles of Law are based on moral Principles and law of nature; it has relation with the State Practice. The statute of the International Court of Justice authorizes the Court to apply the general principles of law recognized by civilized nations in addition to international conventions and custom, which are the two main sources of International law. It makes national legal systems as a source of law for the creation of International Law.
• The special arbitral tribunal between Germany and Portugal also applied the general principles of law in the Maziua and Naulilaa case where the arbitrators observed that in the absence of rules of International law applicable to the facts in dispute, they were of the opinion that it was their duty to fill the gap by principles of equity fully taking into account the spirit of International Law, which is applied by way of analogy and its evolution.

Judicial Decision

• According to Article 38 of the Statute of the International Court of Justice, Judicial Decisions are subsidiary sources of International Law. They are not the automatic sources of law. Judicial Decisions by International Court of Justice, Permanent Court of Justice, International Arbitral Tribunal and Municipal Courts are subsidiary sources of International Law.
• Article 59 of the Statute of the International Court of Justice expressly provides that the decisions of the court have no binding force except between the parties and in respect of that particular case. This means that the judicial decisions are binding only on the disputed States. Under the provisions of this Article, the Court is specifically required not to apply precedent or doctrine of stare decisis in its decisions. Decisions of International Court of Justice are to have only persuasive value. 
• The content of earlier decisions has some element of law and it is clarified, impartially, as certainly carried by International Court of Justice. How it contributes in the development of International Law? Its repeated application is relied upon. Later on, it does not remain only persuasive and it does convert into rules of International Law.

Text Writers, Juristic Works and Commentators

• Text writers, juristic works, and commentators are considered subsidiary sources of international law. When the International Court of Justice (ICJ) makes a decision, it may refer to the opinions of jurists and legal scholars to help determine the rules of international law. While these opinions are not independent sources of law, they can sometimes lead to the formation of international law.
• Juristic writings provide insight into the rules of international law and can simplify the process of framing specific rules. Their value is particularly significant in areas of international law where treaties or customary rules do not exist. For instance, the writings of scholars like Ayala, Gentilis, Grotius, Vattel, Kent, and Zouche have played a role in transforming transient usages into customs and have contributed to the establishment of customary law.
• In cases where the court does not find any treaty, judicial decision, legislative act, or established custom, it may rely on the opinions of jurists as a supplementary means for determining rules of international law. While juristic works are not independent sources of law, they can influence the development of international law, especially in the absence of clear rules.

Equity

• Equity is a principle in international law that emphasizes fairness, reasonableness, and policy considerations in applying established legal rules. While equity is not a direct source of international law, it holds significant importance in areas where clear rules are lacking. Some jurists argue that equity is not a formal source of law but rather a subsidiary source. 
• Equity principles vary from state to state, as they are influenced by the culture and interests of the concerned states. The concept of equity in international law is subjective and often derives from natural law principles. Equity has been referenced in various legal cases, highlighting its relevance in legal decisions.

Decision or Determinations of the Organs of International Institutions

• In contemporary international law, the decisions and determinations made by the organs of international institutions are also recognized as sources of international law. Given the evolving nature of international law, international organizations have become subjects of legal significance. 
• The decisions and determinations made by these institutions contribute to the development of customary rules of international law. As international law continues to change and adapt, the role of international organizations and their decisions becomes increasingly important in shaping legal norms and practices.