Lesson One (1)  : Introduction to International Law 

What is Law?

Law is  the discipline and profession concerned with the customs, practices, and rules of conduct of a community that are recognized as binding by the community. Enforcement of the body of rules is through a controlling authority.


What is International Law?

1- International law, also called public international law or law of nations, the body of legal rules, norms, and standards that apply between sovereign states and other entities that are legally recognized as international actors. The term was coined by the English philosopher Jeremy Bentham (1748–1832).


2- According to Bentham’s classic definition, international law is a collection of rules governing relations between states. It is a mark of how far international law has evolved that this original definition omits individuals and international organizations—two of the most dynamic and vital elements of modern international law. 


3-International law is a distinctive part of the general structure of international relations. In contemplating responses to a particular international situation, states usually consider relevant international laws. Although considerable attention is invariably focused on violations of international law, states generally are careful to ensure that their actions conform to the rules and principles of international law, because acting otherwise would be regarded negatively by the international community.



What are the sources of international law?

International agreements

Customary law

jus cogens (meaning "strong law" or "compelling law")

resolutions passed by international organizations (in some circumstances)

to an extent, decisions of international tribunals, courts, and arbitrations (depending upon the 

underlying agreement to arbitrate)

some general principles of law

judicial decisions and academic treatises (but only as auxiliary sources)

International agreements (such as treaties, conventions, covenants and protocols) between states are the oldest sources of international law. The earliest known treaty dates back to 1380 B.C., to an alliance between the Hittite King Suppiluliuma I and Aziras of Amurru (a North Syrian province of the Egyptian empire).


Customary law is law developed out of a practice by states of adhering to a particular custom out of a sense of obligation.


Jus cogens describes peremptory norms of international law from which no derogation by treaty is permitted. (Vienna Convention on the Law of Treaties, Arts. 53, 64). For example, nations may not contract out of the law forbidding slavery.


In special circumstances, international organizations can create binding law. Resolutions passed by the United Nations Security Council under Chapter VII of the United Nations Charter may be binding on member states (Arts. 41, 42, 48, 49). An example of such a resolution is one that orders sanctions against a state in response to a breach of international law which threatens international peace and security.


Opinions issued by international tribunals (including courts and arbitration) comprise law to the extent that they are binding upon the states-parties to the proceeding. Such decisions are not binding on non-parties, but may serve to reveal the composition of international law to other states and tribunals.


Other sources of international law may be inferred from those available to the International Court of Justice (the "ICJ," also known as "the World Court," the main judicial organ of the United Nations). In addition to the sources already mentioned, the World Court may rely on general legal principles "as recognized by civilized nations" in deducing international law (Statute of the ICJ, Art. 38). The Court may also draw upon, as secondary sources, "judicial decisions and teachings of the most highly qualified publicists of the various nations" in determining the rules of international law (Statute of the ICJ, Art. 38).

International Court of Justice

The primary United Nations organ for the settlement of disputes is the International Court of Justice. Also known as the World Court, it was founded in 1946. Since its founding, the Court has considered over 170 cases, issued numerous judgments and issued advisory opinions in response to requests by UN organizations. Most cases have been dealt with by the full Court, but since 1981 six cases have been referred to special chambers at the request of the parties.