Public international law concerns relationships between sovereign nations

Public international law concerns relationships between sovereign nations


Law[1] is a system of rules, usually enforced through a set of institutions[2]. Public International Law is the law of the political system of nation-states. It is a distinct and self-contained system of law, independent of the national systems with which it interacts, and dealing with relations which they do not effectively govern. In its most general sense, Public International law “consists of rules and principles of general application dealing with the conduct of states and of intergovernmental organizations and with their relations inter se, as well as with some of their relations with persons, whether natural or juridical.”[3] Public International Law actually concerns the structure and conduct of sovereign states.

Public International Law:

International law deals with the acquisition of territory, state immunity and the legal responsibility of states in their conduct with each other. It establishes the framework and the criteria for identifying states as the principal actors in the international legal system. The use of Public international Law has increased due to the increase in global trade, armed conflict, environmental deterioration on a worldwide scale, awareness of human rights violations, and rapid and vast increases in international transportation and a boom in global communications. International law is similarly concerned with the treatment of individuals within state boundaries. There is thus a comprehensive regime dealing with group rights, the treatment of aliens, and the rights of refugees, international crimes, nationality problems, and human rights generally. It further includes the important functions of the maintenance of international peace and security, arms control, the pacific settlement of disputes and the regulation of the use of force in international relations.


International law has existed since the middle Ages but much of its modern corpus began developing from the mid-19th century. Two sophisticated legal systems developed in the Western World: the codified systems of continental European states (Civil Law) and the judge-made law of England (Common Law) the fall of the Roman civilization did not result in the loss of the concepts of Roman law. Starting in the later middle ages, unlegislated Roman law (ius commune or lex mercatoria) was applied by merchants in northern Italian city states and north-western European countries as the basis for commercial (and other) relationships. In the 20th century, the two World Wars and the formation of the League of Nations (and other international organizations such as the International Labor Organization) all contributed to accelerate this process and established much of the foundations of modern public international law. After the failure of the Treaty of Versailles and World War II, the League of Nations was replaced by the United Nations, founded under the UN Charter. The UN has also been the locus for the development of new advisory (non-binding) standards, such as the Universal Declaration of Human Rights. Other international norms and laws have been established through international agreements, including the Geneva Conventions on the conduct of war or armed conflict, as well as by agreements implemented by other international organizations such as the ILO, the World Health Organization, the World Intellectual Property Organization, the International Telecommunication Union, UNESCO, the World Trade Organization, and the International Monetary Fund.


Sources of international law are the materials and processes out of which the rules and principles regulating the international community are developed. They have been influenced by a range of political and legal theories. During the 19th century, it was recognized by legal positivists that a sovereign could limit its authority to act by consenting to an agreement according to the principle pacta sunt servanda[4].

International law has three sources

1) Custom or customary international law (consistent provincial practice accompanied by opinion juries

2) Globally accepted standards of behavior or the practice of the public international law

3) Codifications contained in conventional agreements, generally termed treaties.

In international law, customary law refers to the Law of Nations or the legal norms that have developed through the customary exchanges between states over time, whether based on diplomacy or aggression. Diplomatic following, diplomatic correspondence, policy statements, press release, the opinion of official legal advisers, official manuals on legal questions, international and national judicial decisions, recitals in treaties and other international instruments are considered as the material source of custom. Essentially, legal obligations are believed to arise between states to carry out their affairs consistently with past accepted conduct. These customs can also change based on the acceptance or rejection by states of particular acts. There has been continuing debate over where a distinction should be drawn as to the weight that should be attributed to what states do, rather than what they say represents the law. In its most extreme form, this would involve rejecting what states say as practice and relegating it to the status of evidence of opinion jurist. A more moderate version would evaluate what a state says by reference to the occasion on which the statement was made. It is only relatively powerful countries with extensive international contacts and interests that have regular opportunities of contributing by deed to the practice of international law.

Public International Law and the national Sovereignty:

There is a growing trend toward judging a state’s domestic actions in the light of international law and standards. Numerous people now view the nation-state as the primary unit of international affairs, and believe that only states may choose to voluntarily enter into commitments under international law, and that they have the right to follow their own counsel when it comes to interpretation of their commitments. Certain scholars and political leaders feel that these modern developments endanger nation states by taking power away from state governments and ceding it to international bodies such as the U.N. and the World Bank, argue that international law has evolved to a point where it exists separately from the mere consent of states, and discern a legislative and judicial process to international law that parallels such processes within domestic law. This especially occurs when states violate or deviate from the expected standards of conduct adhered to by all civilized nations.

A number of states support very narrow interpretations of international law, including the People’s Republic of China, the military junta currently holding power in Burma. These states maintain that sovereignty—and thus what some view as the basis of sovereignty, the ultimate ratio regum, or last argument of kings (force and coercion, by military or other means)—is the only true international law; thus seeing states as having free rein over their own affairs and their affairs in the larger world. Other states oppose this view. One group of opponents of this point of view, including many European nations, maintain that all civilized nations have certain norms of conduct expected of them, including the prohibition of genocide, slavery and the slave trade, wars of aggression, torture, and piracy, and that violation of these universal norms represents a crime, not only against the individual victims, but against humanity as a whole. States and individuals who subscribe to this view opine that, in the case of the individual responsible for violation of international law, he “is become, like the pirate and the slave trader before him, hostis humani generis, an enemy of all mankind”[5], and thus subject to prosecution in a fair trial before any fundamentally just tribunal, through the exercise of universal jurisdiction. Another group believes that states only commit to international law with express consent, whether through treaty or customary law[6], and have the right to make their own interpretations of its meaning; and that international courts only function with the consent of states.

Though the European democracies tend to support broad, universalistic interpretations of international law, many other democracies have differing views on international law. Several democracies, including India, Israel and the United States, take a flexible, eclectic approach, recognizing aspects of public international law such as territorial rights as universal, regarding other aspects as arising from treaty or custom, and viewing certain aspects as not being subjects of public international law at all. Democracies in the developing world, due to their past colonial histories, often insist on non-interference in their internal affairs, particularly regarding human rights standards or their peculiar institutions, but often strongly support international law at the bilateral and multilateral levels, such as in the United Nations, and especially regarding the use of force, disarmament obligations, and the terms of the UN Charter.


The principal interest of the Public international law is the relationships between sovereign nations. It has a particular status as law because there is no international police force, and courts lack the competence to punish disobedience. There are disputes about the exact meaning and application of national laws. It is the responsibility of the courts to decide what the law means. In international law interpretation is within the domain of the protagonists, but may also be conferred on judicial bodies such as the International Court of Justice, by the terms of the treaties or by consent of the parties. It is generally the responsibility of states to interpret the law for themselves.


1.       Ian Brownlie, Principal of Public International Law, clarendon press oxford, 4th edn, 1990

2.       E. Lawson, and ML Bertucci, Encyclopedia of human rights, 2nd edn, 1996

3.       Rafael Domingo Osle, The New Global Law, Cambridge University Press, 2010

4.       M. N. Shaw, International Law, Cambridge University Press, 5th edn, 2003

5.       Marmor & Andheri, The Pure Theory of International Law, Hilton, 2002

6.       P.-M. Dupuy & Y. Kerbrat, Droit international public, paris, 10th ed., 2010



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[1] From Old English lagu “Words of Mel”; legal comes from Latin legalis, from lex “law”, “statute” (Law, Online Etymology Dictionary; Legal, Merriam-Webster’s Online Dictionary)

[2] Principal of public international law, the concept of territory, 4th edn( Clarendon press, Oxford, 1990)

[3] Columbia Law School, McKeever, 2003 — Definition of International Law

[4] Schermers-Blokker, International Institutional Law, 943

[5] Janis, M. and Noyes, J. International Law”: Cases and Commentary (3rd ed.), Prosecutor v. Furundžija, Page 148 (2006)

[6] See the customary law in page 3