Sources of international law

Ascertainment of the law on any given point in domestic legal orders is not
Usually too difficult a process. In the English legal system, for example,
One looks to see whether the matter is covered by an Act of Parliament
And, if it is, the law reports are consulted as to how it has been interpreted
By the courts. If the particular point is not specifically referred to
In a statute, court cases will be examined to elicit the required information.
In other words, there is a definite method of discovering what the
Law is. In addition to verifying the contents of the rules, this method also
Demonstrates how the law is created, namely, by parliamentary legislation
Or judicial case-law. This gives a degree of certainty to the legal process
Because one is able to tell when a proposition has become law and the
Necessary mechanism to resolve any disputes about the law is evident. It
Reflects the hierarchical character of a national legal order with its gradations
Of authority imparting to the law a large measure of stability and
Predictability.
The contrast is very striking when one considers the situation in international
Law. The lack of a legislature, executive and structure of courts
Within international lawhas been noted and the effects of thiswill become
Clearer as one proceeds. There is no single body able to create laws internationally
Binding upon everyone, nor a proper system of courts with
Comprehensive and compulsory jurisdiction to interpret and extend the
Law. One is therefore faced with the problem of discovering where the
Law is to be found and how one can tell whether a particular proposition
Amounts to a legal rule. This perplexity is reinforced because of the
Anarchic nature of world affairs and the clash of competing sovereignties.
Nevertheless, international law does exist and is ascertainable.
There

are ‘sources’ available from which the rules may be extracted and
Analysed.
By ‘sources’ one means those provisions operating within the legal
Systemon a technical level, and such ultimate sources as reason ormorality
Are excluded, as aremore functional sources such as libraries and journals.
What is intended is a survey of the process whereby rules of international
Law emerge.
Article 38(1) of the Statute of the International Court of Justice is
Widely recognised as the most authoritative and complete statement as to
The sources of international law. It provides that:
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 recognised
By the contesting states; (b) international custom, as evidence of a general
Practice accepted as law; (c) the general principles of law recognised by
Civilised 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.
Although this formulation is technically limited to the sources of international
Law which the International Court must apply, in fact since the function of the Court is to decide disputes submitted to it ‘in accordance
With international law’ and since all member states of the
United Nations are ipso facto parties to the Statute by virtue of article
93 of the United Nations Charter (states that are non-members of the
UN can specifically become parties to the Statute of the Court: Switzerland