International Law - Public International Law

Public International Law

Public international law (or international public law) concerns the treaty relationships between the nations and persons which are considered the subjects of international law. Norms of international law have their source in either:

1. custom, or customary international law (consistent provincial practice accompanied by opinio juris),
2. globally accepted standards of behaviour (peremptory norms known as jus cogens or ius cogens), or
3. codifications contained in conventional agreements, generally termed treaties.

Article 13 of the United Nations Charter obligates the UN General Assembly to initiate studies and make recommendations which encourage the progressive development of international law and its codification. Evidence of consensus or state practice can sometimes be derived from intergovernmental resolutions or academic and expert legal opinions (sometimes collectively termed soft law).

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. The development and consolidation of such conventions and agreements has proven to be of great importance in the realm of international relations.