Jeremy Bentham coined the expression "international law" in 1780. The System of Public International Law may be defined as "a body of laws, rules, and legal principles based on customs, treaties, or legislation that define, control, constrain (compel) or affect the rights and duties of states in their relations with one another."

Public International Law has grown in use and importance dramatically over the twentieth century, owing to increased global trade, armed conflicts, global environmental deterioration, awareness of human rights violations, rapid and vast increases in international transportation, and a boom in global communications. International law refers to a set of laws that nations view as obligatory on them in their contacts with one another, whether in peace or in conflict, and that compromises sovereign states' rights and responsibilities to one another. It is a system of legal principles that govern how nations interact with one another and with other international players.

It can be defined as the set of rules that govern relationships between states during conflict and cooperation in order to ensure their survival, expressing the will of the ruling classes of the states and defending in the event of a need for coercion applied by states individually or collectively.

Definition
Most of the classical jurists laid down that international law regulates the relation of states with one another, and they therefore have defined the term in this sense only.

1. According to Oppenheim:
   "Law of nations or international law is the name for the body of customary and treaty rules which are considered legally binding by states in their intercourse with each other". The above definition contains three important elements:
   • Firstly, international law consists a body of rules governing the relations between states.
   • Secondly, states regard these rules as being binding on them in their relations with one another. States comply with international law because they feel legally obligated to do so, and not because they want to or are merely morally obligated to do so.
   • Thirdly, such rules derive from customs and treaties.
      
2. According to Starke, International law is "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 includes also:
   1. The rules of law relating to the functioning of international institutions or organizations, their relations with each other and their relations with states and individuals.
   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.

Most of the classical jurists laid down that international law regulates the relation of states with one another, and they therefore have defined the term in this sense only.

This definition of Starke has widened the scope of international law, the scope by stating that along with states international law regulates the rights and duties of international institutions or organizations, individuals, and other non-state entities.

According, Oppenheim:

"It is in its origin essentially a product of Christian civilization and began gradually to grow from the second half of Middle Ages". The claim of the European scholars that the credit of giving birth to International law as we know today, goes to the European countries, is not correct. "The allegation of western Jurists, Oppenheim and others that International Law originated in Europe and is the creation of Western civilization is falsified by a study of the original texts of the 'Ramayana' and 'Mahabharath'." "It leads us nowhere to hold that modern international law is only three or four centuries old. Such an attitude is not only too legalistic, but is clearly disapproved by the present practice which do take account of history."

International law is synonymous with the ' law of nations' which corresponds to French and German equivalents 'droit international' or 'droit des genis'; 'international Recht' or 'volkerecht' and it corresponds to the Italian Spanish equivalents' droitto internazionale' and 'derecho international' respectively.

Bynkershock ascribes the origins of the law of nations to reason and usage basing usage on the evidence of treaties and ordinances. Different names and titles are given to the subject of international law such as Universal Law, Law of Nations, International Public Law, the Law between powers, Inter-State Law, the law of the Community states, Transnational Law

Origin of Public International Law

According to Oppenheim, "It is in its origin essentially a product of Christian civilization and began gradually to grow from the second half of Middle Ages". The claim of the European scholars that the credit of giving birth to International law as we know it today, goes to the European countries, is not correct. "The allegation of western Jurists, Oppenheim, and others that International Law originated in Europe and is the creation of Western civilization is falsified by a study of the original texts of the 'Ramayana' and 'Mahabharath'." "It leads us nowhere to hold that modern international law is only three or four centuries old. Such an attitude is not only too legalistic but is disapproved by the present practice which does take account of history."

International law is synonymous with the ' law of nations' which corresponds to French and German equivalents 'droit international' or 'droit des genis'; 'international Recht' or 'volkerecht' and it corresponds to the Italian Spanish equivalents' droitto internazionale' and 'derecho international' respectively.

Bynkershock ascribes the origins of the law of nations to reason and usage basing usage on the evidence of treaties and ordinances. Different names and titles are given to the subject of international law such as Universal Law, Law of Nations, International Public Law, the Law between powers, Inter-State Law, the law of the Community states, and Transnational Law.

Basis of International Law

There are two main theories which attempt to explain the basis of International Law:

1. Theories as to the law of nature:
   In the 16th and 17th centuries, the jurists were of the view that international law is based on the law of nature. According to this theory, International law has been followed by the states because it is the law of nature which is the higher law. According to them, natural law confers binding force on International law. According to Grotius natural law, is the 'dictate of right reason'. This theory has been criticized the definition of the term 'natural law' is very vague and uncertain as each follower gives a different definition.
   
   Different meanings are ascribed such as reason, justice, utility, the general interest of the international community, etc. It must be admitted that the law of nature has greatly influenced the growth of international law, but the theory is not based on realities and actual practice of the states.
    
2. Positivism:
   This theory is based on the actual practice of the states. It has been pointed out that the will of states is the main source of international law and is binding because states have consented to the rules of international law.

Starke has rightly stated: "International law can in logic be reduced to a system of rules depending for their validity only on the facts that states have consented to them. According to Italian Jurist, Anzillotti, the binding force of international law is based on a fundamental principle known as 'Pacta Sunt Servanda'(agreements entered into by states must be respected and followed in good faith). However, the Positivist Theory fails to explain the binding force of customary rules of International Law.

Criticism:
Many jurists have criticized this theory, following are the main points of criticism:

• The concept of the will of the state is metaphorical. The will of the state is nothing but the will of the people who compose it.
• It fails to explain the case of the admission of a new state into the family of nations. When a state is admitted to the family of nations, international law becomes applicable to it even without its consent.
• The positivists have based their theory on consent which has been severely criticized by the jurists.
• In practice, it is never necessary to show in regard to any particular rule of customary international law that the states have given their consent.
• There are certain principles of international law that are applicable to non-members of the U.N. although they had never given their consent for it.

Some other Theories regarding the basis of International Law

Apart from the above-mentioned theories, there are some other theories regarding the basis of International Law:

1. Theory of consent: The theory of consent is based on the Positivists theory which has been criticized earlier. It fails to explain the basis of international law. According to this theory, states observe the rules of international law because they have given their consent.
   
   The points of criticism are as follows:
   1. As regards customary rules, it is not necessary to prove that states have given their consent.
   2. In regard to customary rules, the basis of implied consent is far from correct.
   3. It fails to explain the case of recognition of a new state.
   4. It fails to explain the true basis of international law.
       
2. Auto-Limitation Theory: Yet another theory based on the theory of consent which fails to explain the basis of international law. It is presumed that states have a will. Moreover, Auto-Limitation is no limitation at all.
    
3. Pacta Sunt Servanda: According to Anzillotti, the binding force of International Law is based on a fundamental principle known as Pacta Sunt Servanda which means, agreements entered into by the states must be respected and followed in good faith. Nevertheless, this theory also fails to explain the binding force of customary rules of international law. As an author rightly remarks, "The realization that international customary law does not rest on agreements and that the tenet of Pacta Sunt Servanda is itself a rule of customary law led to new formulations of basic norms."
    
4. Theory of fundamental rights: As this theory is based on the naturalistic view, it is contended that like man, states also possess certain fundamental rights because so far there is no world authority over and above the states. This theory has also been criticized because it fails to explain the basis of international law.

The subject of International Law
A subject of rules is a being upon which the rules confer rights, and capacity and impose duties and responsibility. Generally, it is the State who enters into treaties with each other and is thus bound by its provisions. This does not however mean that other entities or individuals are outside the scope of international law. International law applies to individuals and certain non-state entities in addition to states. In the modern era international law has expanded a lot. Now this law is applied to States and individuals.

Theories regarding Subjects of International Law:

The following are the three main theories prevalent in regard to the subjects of international law:

1. Only States are the subject-matters of International Law/Realistic Theory:
   Certain jurists have expressed the view that only International law regulates the behavior of states hence states are its subject matters. Percy E. Corbett says, "The triumph of positivism in the late eighteenth century made the individual an object not a subject of international law. Criticism:- The jurists have bitterly criticized as this theory fails to explain the case of slaves and pirates. The pirates are regarded enemy of humanity and they can be punished by the State for piracy. In the international arena by some ordinary treaties communities of states have granted certain rights. But those jurists who say that states are the only subject matter of international law but are an object of it. To say that individuals are not the subject but object of the International law seems to be incorrect. Prof. Schwarzenberger, has aptly remarked that this view is controversial. He asserts that he individual who is the base of the society is only an object of the I. Law is not justified.
    
2. Only individual are the subjects of International law/Fictional Theory:
   Just contrary to the above theory there are certain jurists who have expressed the view that in the ultimate analysis of international law, it will be evident that only individuals are the subject of International Law. The main supporter of this theory is Professor Kelson. Before Kelson this view was expressed by Westlae, who opined, the duties and rights of the States are only the duties and rights of men who compose them. Kelson has analysed the concept of State and according to him it is a legal concept which as a mixture of legal rules applicable to all the people living in certain area hence the obligations of a State in international law in the last resort are the duties of individuals of which state consists. In fact there is no difference between international law and state law. In his view, both laws apply to the individuals and they are for the individuals. However, he admits that the difference is only this state law applies to individuals immediately whereas international law applies to individuals immediately.
   
   Criticism: So far as logic is concerned the view of Kelson seems to be correct. An example is the Convention on the Settlement of Invest Disputes between States and Nationals of the other states, 1965. By this treaty, a provision is made to settle the disputes which arise from the investment of capital by nationals of one state in other states. So it is clear that the view of Kelson that international law is made applicable through the medium of a State seems justified.
    
3. States individuals and certain non-state Entities are Subjects/Functional Theory:
   This view seems to be justified as against the above views. In support of this, the following reasons may be advanced:
   
   • In modern times many treaties grant rights and duties to individuals.
   • In the case of Danzing Railway PCIJ-1928, in case the State Parties of a treaty intended to grant rights to individuals then International Law would recognize such rights and the International Court would enforce them.
   • Geneva Convention of Prisoners of War-1949 has also accorded certain rights o prisoners of war.
   • According to Nuremberg Court since crimes against International Law are committed by individuals the provisions of International Law can be enforced.
   • Genocide convention- 1948:- In the convention also individuals have been assigned directly certain duties. By article 4 of this convention those individuals who commit international crime of genocide should be punished whether they are public servants or ordinary person.
   • By the above description it is clear that only states are not subject matter of Internationals Law but in modern times individuals international Institutions, Non-state entities minorities are also the subject-matter of International Law.
   • Place of Individuals in International Law:- As pointed out earlier individuals are also treated to the subjects of international law although they enjoy lesser rights than states under international law. In the beginning they were accepted as subjects of international law as an exception of the general rule and number of jurists treated them as objects rather than the subject. In the recent times several treaties concluded wherein rights have been conferred and duties have been imposed upon the individuals.
   • Geneva Convention of Prisoners of War-1949 has also accorded certain rights o prisoners of war.
   • According to Nuremberg Court since crimes against International Law are committed by individuals the provisions of International Law can be enforced.
   • Genocide convention- 1948:- In the convention also individuals have been assigned directly certain duties. By article 4 of this convention those individuals who commit international crime of genocide should be punished whether they are public servants or ordinary person. By the above description it is clear that only states are not subject matter of Internationals Law but in modern times individuals international Institutions, Non-state entities minorities are also the subject-matter of International Law.
      

Place of Individuals in International Law:

As pointed out earlier individuals are also treated to the subjects of international law although they enjoy lesser rights than states under international law. In the beginning they were accepted as subjects of international law as an exception of the general rule and number of jurists treated them as objects rather than the subject. In the recent times several treaties concluded wherein rights have been conferred and duties have been imposed upon the individuals. Some of the provisions are as under:-

• Pirates: Under International Law pirates are treated as enemies of mankind. Hence every state is entitled to punish them.
• Harmful acts of individuals: - For the amicable and cordial relation of the state it is necessary that the individuals should not be involved in such acts as may prove detrimental for the good relations among states. A leading case ex parte Petroff-1971, wherein two persons who were found guilty of throwing explosive substances on the Soviet Chancery were convicted.
• Foreigners: To some extent international law also regulates the conduct of the foreigners. According to international law it is the duty of each state to give to them that right which it confers upon its own citizens.
• War criminals: can be punished under international law.
• Under some treaties individuals have been conferred upon some rights whereby they can claim compensation or damages.

Conclusion
To conclude, slowly and gradually individuals are occupying place of importance under international law. They are no more mere objects of international law. They are in fact the subjects of international law. Public International Law has increased in use and importance vastly over the 20th Century, due to the increase in global Trade, armed Conflicts, Environmental deterioration on a world wide scale, awareness of human rights violations, rapid and vast increases in International Transportation and boom in global communications. It cannot, however, be denied that even today states are the main subjects of International law and the bulk of international law deals with their rights and duties. The rise of international law mainly happened during the 19th Century with the rise of powerful states surrounding Europe. With the greater technological advancement and development of new warfare methods, it became necessary to regulate the behavior of these states with the help of a legal framework.

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