International law is "[t]he legal system governing the relationships between countries; more modernly, the law of international relations, embracing not only countries but also such participants as international organizations and individuals (such as those who invoke their human rights or commit war crimes). — Also termed public international law; law of nations; law of nature and nations; jus gentium; jus gentium publicum; jus inter gentes; foreign-relations law; interstate law; law between states (the word state, in the latter two phrases, being equivalent to nation or country)".
Other definitions of International Law include:
- “[I]nternational law or the law of nations must be defined as law applicable to states in their mutual relations and to individuals in their relations with states. International law may also, under this hypothesis, be applicable to certain interrelationships of individuals themselves, where such interrelationships involve matters of international concern.”
- “International law is the legal order which is meant to structure the interaction between entities participating in and shaping international relations. This rather wide definition deliberately avoids a reference to States. Although States play a significant role in today's international relations, they are not the only actors. International organizations and other international law subjects, as well as groups of individuals, non-governmental organizations, and even individuals, contribute to the development of international relations. The development that groups of individuals and individuals participate in international relations acting on their own and not on behalf of States is a recent one.”
International Law, Black’s Law Dictionary (12th ed. 2024).
Types of International Law
- Public International Law - Governs the relations between nations and sets forth mandates for those nations to abide by.
- Private International Law - Deals with conflicts between private actors in situations where more than one nation's law may apply.
International Law, Wex, https://www.law.cornell.edu/wex/international_law (last updated July 2023).
Sources of International Law
Article 38 of the Statute of the International Court of Justice lists four principal sources of international law: conventions/treaties, customary law, general principles of law, and judicial decisions/scholarly articles.
- Primary Sources
- Treaties are binding agreements between nations that govern the rights and obligations of participating countries.
- Customary law arises from patterns of behavior in nations. States follow certain practices for a period of time out of a sense of obligation, and those practices develop in international law.
- General principles of law are aspects of common law shared by most countries in the world.
- Secondary Sources
- Judicial decision and scholarly articles rarely play a role in international law when the prior three fail.
International Law, Wex, https://www.law.cornell.edu/wex/international_law (last updated July 2023).
Email a member of the reference staff at referencelaw@nccu.edu.