There is no centralized law-making power in international law. In many legal systems, the source of law can be found such as the written constitution of the state, by way of an official legislature and its national courts. However, in the world of international laws there are no such law-giving sources to which all the members of the community can refer to. In the nonappearance of these, the sources that are listed in Article 38(1)(a)-(c) is used as a starting point of sources of international law1. This essay will focus mainly on whether there is a hierarchy between sources of international law.
Article 38 of the Statute of The ICJ provides that:
“1- The court, who’s function is to decide in accordance with international law such disputes as are submitted to it, shall apply:
International conventions, whether general or particular, establishing rules expressly recognized by the contesting states;
International custom, as evidence of a general practice accepted as law;
The general principle of law recognized by civilized nations;
Subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicist of the various nations, as subsidiary means for the determination of rules of law.”2
This means that all sources of international law are binding. However, it does not acknowledge to be a correct or complete statement of the sources of international law. There is no word of ‘source’ in the above article3. Furthermore, some exceptions must be mentioned like the Vienna Convention on the Law of Treaties. The notion of jus cogen was introduced in that treaty as being superior to the dispositive norm of international law, which has been acknowledged universally. A former judge of the international court of justice said that, “although lawyers know that the quality of certainty of law is one on which there must be much compromise, not least in the interest of justice, it is a desideratum of any strong law that there is reasonable certainty about where one should look to find it”4. Furthermore, jus cogen may have hierarchical superiority, but there is insufficient practice as to whether these peremptory norms derive from traditional sources of international law and the relationship between norms of jus cogen and standards norms of international law (jus dispotivum). Some might find that Article 38 provides certainty on where to find the exact sources of international law which either creates law or identifies law and place them into a hierarchy5. On the other hand, Article 38 does not provide an unambiguous statement of sources of International Law. This has not stopped authorities by the courts, by the states themselves, and by national courts6 in accepting that Article 38 is a clear and precise statement that they could rely on.
Article 38(1) of the ICJ statute does not ascertain a hierarchy of the sources, but for evidentiary reasons it is easier to go back to a written form of legal obligation, example a treaty, than going back to unwritten forms of law like the general principle7.
The statute has no mention of the UN Security Council or the UN General Assembly resolutions, as the two have immense importance and significance for deliberation of contentious judgment and advisory opinion8. Treaties and treaty-making have become the most frequently relied upon sources in regards to international conduct9, conversely because the General Assembly are recommendations10, they lack the indispensable opinio juris for custom. The reason why it has sometimes been criticized is that most states will repeatedly vote for resolutions that they stand for. An example of this would be when states voted for resolutions which condemn state-sponsored torture, but some of these countries are actively engaged in the torture of their citizen. One author goes further to ask the question “Which would we prefer to believe: the professed position of the state, or the empirical evidence of its actual conduct?”11.
It is also worth mentioning, that some perceive international law as being an international political order, “So long as international law was designed to facilitate international order it was circumscribed in key ways: states were the political subjects and agents of international law; international law was concerned with the regulation of inter-state relations: and the scope of international was confined to the question of order.”12.
When it comes to the relationship between customary law and treaties, there is a general agreement that Article 38 does not establish a hierarchy13. They are found to exist alongside each other in no particular order of superiority. Furthermore, when a norm is created via one or the other source listed in Article 38, it is thought to have no relevance to its authority or legality14, “At a practical level, the absence of inherent hierarchies among sources of international law means that adjudicators are left to resolve conflicts of norm and on an ad hoc basis by means of interpretative techniques (e.g., harmonious interpretation) or conflict resolution principles (e.g., jus corgen, lexs pecialis, lex posterior).”15. The order in which Article 38 is presented is justified by the difficulty of identifying certain norms on on the basis of respective sources, which entails that all sources of international law are equally binding.
An exception to this would be an example with the use of force, which is connected with the interpretation and application of the UN Charter, which raises the question if the UN Charter is binding on non-member states. Article 103 of the UN Charter provides that where there is disagreement between obligations deriving from the Charter and obligations based on other sources, the Charter based would take superiority over all others. This came from Article 20(1) of the Vienna Convention on the Law of Treaties which recognizes Article 103 as an exception to the rule lex posterior16. Article 103 would be the first contender for claiming a hierarchically superior status (apart from from jus corgen). However, not everyone would agree to this. Some authors believe that it establishes a conflicting rule17.
One author argues that because of the absence of rigid and formal hierarchies in the doctrine of sources means that adjudicators and legal scholars have expressed their own fondness for particular sources, which establishes a sort of informal hierarchy between them18. Additionally, a system of law that lacks certainty has an advantageous effect because it means less entrenches disputes19.
When it comes to incorporating the general principle as international legal rules, there might be a slight contradiction “The more abstract the principle, the greater consensus of legal systems, but also the less useful the rule”, “the less abstract (and more concrete) the principle, the more useful it is, but also the more difficult it is to find a consensus among domestic legal systems”20.
Article 38(d) states that judiciary decisions and highly qualified publicists are a merely subsidiary source of international law which is placed at the bottom of the hierarchy and this may embody an inaccurate representation of the practice.
The uncertainty of a hierarchy arises in some areas where a rule of customary law comes into force after the formation of a treaty. Doubts, whether the treaty or the rule of custom should take precedence over the other, is unclear. If the treaty would have priority, then, hierarchy as listed in Article 38, would be correct. If the rule of custom would override the treaty, then it would show that customs and convention are at equal ranks. The lack of explicitly of Article 38 would not be able to identify this problem. Moreover, the ICJ attempted to avoid this situation by interpreting treaties to complement the customary rule rather than contradict it. In Danube Dam Case21, the treaty in question was understood to be capable of it effects being modified in the light of later custom. The ICJ ruled that “the law of treaties and the law of State responsibility” were “two branches of international law that obviously have a scope that is distinct”.
In conclusion, some jurists suggest that because Article 38 was devised in 1920, it can not cope with the “brave new world” of organized international communication and co-operation. Developments and codification of international law, for example, the International Law Commission, the General Assembly, and unilateral acts of states, paired with the notion of jus corgen, are all probable to be sources of international law. Even though resolutions have no legal obligations22, they do have a significant influence on states actions and they contribute to the development of the law “General Assembly resolutions, even if they are not binding, may sometimes have a normative value. They can, in certain circumstances, provide evidence important for establishing the existence of a rule or the emergence of an opinio juris.”23.