Traditional Definition of International Law

Oppenheim Definition
According to Prof. L. Oppenheim:
Law of Nations or International Law is the name for the body of customary and conventional rules which are considered legally binding by the civilized states in their relationship with each other.

The definition mentioned international law as the body of customary and conventional rules. Here, customary rules are the rules which a state follows consistently for a long period of time. For Example- Sri Lanka has been taking water from the Palk Strait for a long period of time. And conventional rules are those rules which two or more countries by an agreement agree to a certain set of rules which are acceptable for them for a long period of time.

There are three components discussed in the Oppenheim definition.

1. Firstly, there is a body of rules used to govern the relations between states.
2. Secondly, the state considers these rules binding on them in their relation with other states. And lastly, these rules are derived from customs and treaties.

Mentioning International law as a 'body of rules' denotes that it is static in nature. With ever changing human nature and interest it becomes difficult to deal with a static body of rule. Therefore, it should be dynamic in nature and not static.

Also, the definition mentions only states as subjects of International law. Other subjects of International law like International Organisations, individuals were nowhere mentioned in Oppenheim definition.

The definition including the term civilised states was also criticised. Here, civilised states include only Christian community states.

Criticism of Oppenheim's definition:
By referring to International Law to only civilized states without giving any reasonable cause, the definition is creating an abnormal differentia among the states.

And lastly, the definition mentions only customs and treaties as sources of International law. But, it is explicitly mentioned in Article 38 of the statute of ICJ, that along with customs and treaties, General Principles of law are also considered as primary sources of International law.

Torsten Gihl Definition
Later, a new definition of International law was framed by Torsten Gihl which says:
The term International Law means the body of rules of law, which apply within the International Community or society of States.

Now, this definition of Gihl includes two terms such as international community and Society of states. The term international community is itself broader in nature because it includes the United Nations as well along with other states. Whereas Society is states is a term which is narrow in nature.

Lord Coleridge, C.J., defined International law as:
The law of nations is that collection of usages which civilized States have agreed to observe in their dealings with one another.

This definition of Coleridge includes the term 'collection of usages' which means customary rules. Therefore, the definition includes only customs as a source of International law.

Overview of the Traditional Definition of International Law

Oppenheim and other scholars' definitions mentioned only states as subjects of International law. Other subjects of International law like International Organisations, individuals were nowhere mentioned in the Traditional definition of International law.

Also, as per traditional definition sources of International law are basically customs and treaties. General Principles of law were nowhere mentioned as sources of International law.
The definition was also restricted to civilised states i.e. Christian community states.

Modern Definition of International Law

As per J.G.Starke:
International Law may be defined as that body of law which is composed for its greater part of the principles and rules of conduct which states feel themselves bound to observe, and therefore, do commonly observe in their relations with each other, and which also includes:

1. The rules of law relating to the functioning of international institutions or organisations, their relations with each other, and their relations with states and individuals; and
2. Certain rules of law relating to individuals and non-state entities so far as the rights or duties of such individuals and non-state entities are the concern of the international community.

Implications of Modern Definition

State is considered to be the primary and original subject of International law.

However, it also regulates the action of other entities as well:

1. Individuals:
   Common people of any state are also believed to be the subject of international law.
   
   The question of whether individuals can be regarded as subjects of international law emerged at the end of the Second World war.
   
   At the end of second world war, Nazi official war criminals were prosecuted by International Tribunal, also known as Neurenberg trials. The Neurenberg Tribunal was basically formed to prosecute Nazi officials.
   
   And it was realised that not only states but individuals also have the responsibility under international criminal law.
   
   Hence, aftermath of the second world war was:
   
   1. Development of International Criminal law and
   2. Development of Human rights (UDHR, ICCPR, CEDAW)
   Because of the aftermath of the second world war, it was realized that if individuals have rights to possess and enforce then individuals must be considered as one of the subjects of International law.
   
   And since then, individuals i.e. common people of any state are considered to be subjects of international law.
   
   For Example- Say a homosexual act was done by Mr. A in Ireland. Since homosexual conduct is still not appreciated in Ireland, therefore, Mr. A was prosecuted for the same. Now, Mr. A feels that his human rights have been violated. In such a scenario, where the domestic court remedies are exhausted, Mr. A can approach the International community like the American Court of Human rights for remedy.
   
   The following are the pointers which an individual must keep in mind while approaching the International Community like The European Court of Human rights, American Court of Human rights:
   
   1. There must be a violation of Human rights.
   2. Principle of natural justice is not followed.
   3. Domestic court remedies are exhausted.
   We can also refer to the Kulbhushan Jadhav case, In this case an Indian naval officer was captured by Pakistan officials. The officer was prosecuted in the Pakistan court and no fair trial was given to him. Since, there was direct violation of human right and also principle of natural justice was not followed, therefore, India approached the International community i.e. International Court of Justice (ICJ) for the remedy.
    
2. Non-state entities:
   The entities which are not registered/recognised as states by the International community like the United Nations are referred to as Non-state entities.
   For Example:
   
   1. After the second world war, Germany expelled all the Jews. Therefore, the remaining
      Jews went to the International community i.e. The League of Nations to provide them with an independent territory at Jerusalem (now Israel). The area provided to the Jews included people such as Arabs who were already residing there. And these Arab people were resilient in leaving that place because Jerusalem was also considered sacred for them. Later on, Israel occupied most of the territory and till date Palestine is not recognised as a state.
      
      Therefore, Palestine can be considered as a non-state entity.
      
      Another example of a non-state entity could be that of China which basically consists of two domains- South b) Republic China and Taiwan.
      Where Taiwan is considered as a non-state entity.
       
3. International Organizations:
   These are also considered as subjects of international law as per the modern definition.
   International organisations are established by states through international agreements and their powers are limited as per the constituent document. Example- United Nations (UN).
   
   The powers of the United Nations are set out in the United Nations Charter of 1945. The main UN judicial organ i.e. The International Court of Justice (ICJ)has the power to deliver binding decisions on the question of International law which has been referred to by various states. ICJ also has the power to give advisory opinions to the U.N.

Minorities and Indigenous people:

These groups of people are also considered as subjects of International law.

After the first world war, the major problem which came out was to protect the minority groups in Europe. The international community i.e. the League of Nations assumed its responsibility in order to protect the rights of minorities in Europe in various aspects like education, health and fair labour standards.

Indigenous people are considered to be a specific part of minority groups with special needs.

The traditional view was basically restricted in considering only states as the subjects of international law, whereas the modern definition expanded its subjects of international law. Individuals, international organisations, non-state entities and minorities groups are also the subjects of international law as per the modern definition.

Apart from this, the modern definition emphasised on the point that states feel bound to follow the rules of conduct laid down in the body of law which is referred to as international law. Such rules of law help in governing the relations amongst various states and also relations between states and its individuals.

The modern definition is also considered the rights of individuals, non-state entities, minority and indigenous people.