Introduction
Public International Law and national law (municipal law as known in the Common Law Countries) are two legal systems. National law governs the domestic (internal) relations between the official authorities of a State and between these authorities and individuals as well as the relations between individuals themselves. Public International Law governs primarily the relations between States.
With the rise and extension of Public International Law, a question begins to arise as to the relationship between the national law of the States and the Public International Law. This question gives rise to many practical problems. What is the status of the rules of Public International Law before a national court? What is the status of the rules of national law before an international court? Which rule does prevail in a case of conflict between the two laws? How do rules of Public International Law take effect in the internal law of a State?
The answers to the above questions are presented in the following sections: section one deals with the theories dealing with the relations between International Law and national law; section two deals with the attitude of International Law to national law; and section three deals with the attitude of various national laws to International Law.
The Theories Dealing with the Relations Between International Law and National Law
There are two major theories on the relationship between Public International Law and national law.
- The first is the dualist theory.
- The second is the monist theory
The dualist theory considers that International law and national law are two separate legal systems which exist independently of each other. Each of these two systems regulates different subject matters, function on different levels, and each is dominant in its sphere. Public International Law primarily regulates the conduct of sovereign States. National law regulates the conduct of persons within a sovereign State. On this view, neither legal system has the power to create or alter rules of the other. When national law provides that International Law be applied in whole or in part within the jurisdiction, this is merely an exercise of the authority of national law in the adoption or transformation of the rules of International Law into its legal system. The national law has a supremacy over the International Law; in the case of a conflict between International Law and national law, a national court would apply national law.
The monist theory, which upholds the unity of all law, regards International Law and national law as forming part of the same legal system (order). It argues that both laws are based upon the same premise, that of regulating the conduct and the welfare of individuals. However, it asserts the supremacy of International Law over national law even within the national sphere; in the case of a conflict between the two laws, International Law is supreme.
It is notable that the position taken by each of these two theories is a reflection of its ideological background. The dualist theory adheres to positivism, while the monist theory follows natural law thinking and liberal ideas of a world society.
Facing these two basic theories, a third approach is introduced. This approach is somewhat a modification of the dualist theory. It attempts to establish a recognized theoretical view tied to reality. While it asserts that the two laws are of two distinct legal systems, it denies that a common field of operation exists as between International Law and national law by which one system is superior or inferior to the other. Each law is supreme in its own sphere (field). Just as one cannot talk in terms of the supremacy of one national law over another, but only of two distinct legal systems each operating within its own field, so International Law and national law should be treated in the same way. Each law exists within a different juridical order.
Because the above opposing theories, in reality, do not adequately reflect actual State practice, the scholars in each side have forced to modify their original positions in many respects, bringing them closer to each other, without, however, producing a conclusive answer on the true relationship between International Law and national law. This fact has led some legal scholars to pay less attention to these theoretical views and to prefer a more empirical approach seeking practical solutions in a given case. The method of solving a problem does not probe deeply into theoretical considerations, but aims at being practical and in accord with the majority of States practice and international judicial decisions. On this view, it is more useful for us to leave the theoretical controversy aside and direct our attention to the attitude of International Law to national law and the attitude of the various national laws to International Law; these are what are discussed in the following two sections.
The Attitude of International Law to National Law
International Law, in the international sphere, has a supremacy over national law. However, this principle does not mean that national law is irrelevant or unnecessary. International Law does not ignore national law. National law has been used as evidence of international custom or general principles of law, which are both sources of International Law. Moreover, International Law leaves certain questions to be decided by national law. Examples of these questions are those related to the spheres of competence claimed by States as regards State territory, territorial sea, jurisdiction, and nationality of individuals and legal persons, or those related to obligations to protect human rights and the treatment of civilians during belligerent occupation. Thus, the international court may have to examine national law related to these questions in order to decide whether particular acts are in breach of obligations under International Law, particularly, treaties or customary law.
A great number of treaties contain provisions referring directly to internal law or employing concepts which by implication are to be understood in the context of a particular national law. Many treaties refer to “nationals” of the contracting parties, and the presumption is that the term means persons having that status under the internal law of one of the parties.
The international courts, including the International Court of Justice and its predecessor, have regarded national law as a fact that the parties may provide by means of evidence and not to be taken by the court ex officio. Moreover in examining national law the courts have in principle regarded as binding the interpretation by national courts of their own laws.
The Attitude of National Laws to International Law
The attitude of national law to International Law is not that easy to summarize as the attitude of International Law to national law. This is because the laws of different States vary greatly in this respect. However, States are, of course, under a general obligation to act in conformity with the rules of International Law; otherwise, they will be responsible for the violations of such rules, whether committed by their legislative, executive or judicial authority. Further, States are obliged to bring national law into conformity with their obligations under International Law; for example, treaties may require a national legislation to be promulgated by the States parties. Nevertheless, International Law leaves to States the method of achieving this result. States are free to decide how to include their international obligations into their national law and to determine which legal status these have internally. In practice, on this issue there is no uniformity in the different national legal systems. However, the prevailing position appears to be dualist, regarding International Law and national law as different systems requiring the incorporation (adoption, transformation and reception are other concepts used) of the international rules on the national level.
Actually, the most important issues of the attitude of national legal systems to International Law concern the status of international customary law and international treaties. On these issues, the attitude of various national legal systems varies.
The survey of the attitudes adopted by various countries of the Common Law and Civil Law traditions leads to the following conclusions. The first of these is that most countries accept the operation of customary rules within their own jurisdictions, providing there is no conflict with existing laws, i.e., if there is a conflict, national law is supreme; some countries allow International Law to prevail over national law at all time.
The second conclusion is that as regards treaties, in some countries, certain treaties operate internally by themselves (self-executing) while others require undergoing a process of internal legislation. Some countries allow treaties to supersede all national laws (ordinary laws and the constitution), whether made earlier or later than the treaty, while others allow treaties to supersede only ordinary laws and only that made earlier than the treaty. Others adopt opposite positions.
