1. Sources of International Law

2. What Is International Law?
A rule that has been accepted as such by the International community

3. Customary Practices
Countries may follow, in the absence of any formal written agreements, to engage in practices they feel ethically bound to follow
Eg. Diplomatic immunity principle was followed long before it was codified

4. Formal Agreements
Most common means of establishing rule internationally is through formal agreements
Treaties
Conventions
Protocols
Covenants
Acts

5. Formal Agreement
Treaties typically deal with obligations that will be imposed on signing countries
Treaties might deal with political actions (eg. declaration of war and peace or creation of formal alliances)
Treaties may also govern areas such as trade, commerce and natural resources

6. General Principle
Article 38 of the Statute of the International Court of Justice list general principles of law recognized by “civilized nations”
These principles provide a mechanism for addressing international issues

7. Article 38
The Statute of the International Court of Justice, part of the Charter of the United Nations, defines the sources of international law in the following language:
Article 38. (1) The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:
(a) international conventions, whether general or particular, establishing
rules expressly recognized by the contesting states;
(b) international custom, as evidence of a general practice accepted as law;
(c) the general principles of law recognized by civilized nations;
(d) subject to the provisions of Article 59, judicial decisions and the
teachings of the most highly qualified publicists of the various nations, as
subsidiary means for the determination of rules of law,

8. Judicial Decisions and Teachings
Decisions made by the International Court of Justice and domestic courts are considered to be of persuasive value
Means these decisions can be consulted but they have no binding force