The sources of international law can be divided into following categories:
- International conventions.
- International customs.
- General principles of law recognized by the civilized states.
- Decisions of judicial or arbitral tribunals and judicial works.
- Decisions or determinations of international organizations.
Article 38 of International Court of Justice (ICJ) recognized the following sources for IL:
- 1. International conventions.
- 2. International customs.
- 3. General principles of law recognized by the civilized states.
- 4. Decisions of judicial or arbitral tribunals and judicial works.
International conventions- Art 38 of ICJ consider it as the first source of IL. A/c to Hudson Conventions is used in a general and inclusive sense. It would seem to apply to any –treaty, agreement, and protocol. A convention may be general either because the numbers of parties or character of it or it may be particular which deals with specific parties.
Whenever an international tribunal decides any disputes between any states, it first seeks whether there is any treaty between the parties if there is a treaty between the parties the tribunals is bound to follow the rules laid down by the respective treaty. As schwarzenberger rightly describe the treaty – treaty are agreement between subjects of international law creating a binding obligations in international law.
Reference can be made by Art 26 of Vienna Convention on the law of treaty which applies the rule of Pacta Sunta Servanda – means treaty is the binding force upon the party and it must be performed by them in a good faith.
Protocol is the supplement of treaty, it use as a modification of treaty.
Vienna Convention on the law of Treaties –
It is of two kinds
- Law making treaties.- this type of treaties perform the same functions in the international field as legislation does in the State files. it can again be divided into two types-
- I. Treaties enunciating rules of International law- example UN charter.
- II. International treaties which lay down general principle.- example Geneva Conventions on the law of sea, and Vienna Convention on the Law of Treaties.
- Treaty contract. In this treaty two or more State are entered into contract sort of thing. And these treaties are binding on the parties.
- International Customs.- it is the oldest and the original source, of international as well as of law in general. Customary rule are the rules which have been developed in a long process of historical development. The customs arose from the natural principles of justice and public utility. The sanction of the custom means the people of the nations accepted it. And it deserved the sanction of law also. As Salmond rightly said- customs is to society and law is to sate. Art 38(b) of ICJ recognizes custom as evidence of general practice accepted by law.
In order to understand the meaning of custom we have to understand the meaning of usages. Usage is in fact is the early stage of custom. In other words those habits which are often repeated by the States. –Satrk- where a custom begins where usages ends.. usage is an international habit of action that has yet not received full legal attestation. It is not necessary that usages always become the custom.
Ingredients of Customs-
- 1. Long duration.
- 2. Uniformity.
- 3. Generality of practice.
- 4. Acceptance of law.
- 4. General principle of law recognized by civilized state. Means those rules which we find repeated in much the same from in the developed systems of law, either because they have a common origin as in Roman law or because they express a necessary response to certain basic needs of human associations.
International court has recognized the general principle of law such as- good faith, responsibility, prescription, res judicata etc.
- 5. Decisions of Judicial or Arbitral Tribunals and Justice Works-
ICJ decisions- it is the main international judicial tribunal, but it is to be noted that its decisions are not binding nature. Art 59 of ICJ says that- no binding force except between the parties and in respect of that particular case.
Jurist Work- although juristic works cannot be treated as an independent source of international law yet the view of the jurist may help in the development of law.
- International organizations- such as WTO,WHO etc.
- Other source of International Law-
- I. International comity – the mutual relation of states are based on the principle of comity, when a state behaves in a particular way with other states, the later have also to behave in the same way.
- II. State paper- when one state send letters to each other for mutual interests. These letters are sometimes published. A study of these letters sometimes revelas that certain principles are repeatedly followed by states in their mutual intercourse.