What is international law and where does it come from?
Describe the nature of international law and its main sources, and explain how it differs from domestic Australian law.
What international law is, its main sources including treaties and customary law, and how it differs from domestic Australian law.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
What this dot point is asking
This dot point asks you to describe what international law is, where it comes from, and how it differs from the law made inside Australia.
What international law is
International law is the set of rules that governs the conduct of nation states and international organisations in their dealings with one another. It covers matters such as the use of force, trade, the environment, the law of the sea, diplomatic relations and human rights. It is sometimes called public international law to distinguish it from the rules governing private cross-border disputes. Because it operates between sovereign states rather than over individuals within one country, it works differently from the domestic law studied in the rest of this course.
The main sources of international law
The accepted list of sources comes from Article 38 of the Statute of the International Court of Justice:
- Treaties (also called conventions or covenants): written agreements between states that are binding on those states that agree to them. Examples include the United Nations Charter and the International Covenant on Civil and Political Rights.
- Customary international law: rules that develop because states consistently act in a certain way (state practice) out of a sense of legal obligation (opinio juris). An example is the long-standing immunity of diplomats.
- General principles of law: principles common to the major legal systems of the world, such as good faith and fairness.
- Judicial decisions and the writings of leading scholars: these are subsidiary sources that help interpret and clarify the law.
How international law differs from domestic law
The contrast with Australian domestic law is the key point:
- Law-maker: domestic law is made by a sovereign parliament; international law has no world parliament, so states create law mainly by agreeing to it.
- Enforcement: domestic law is enforced by police, courts and prisons; international law has no equivalent enforcement body, and bodies such as the United Nations have limited power to compel states.
- Jurisdiction: domestic courts have compulsory jurisdiction over people in their territory; the International Court of Justice can usually only hear a dispute if the states involved consent.
- Basis of obligation: domestic law binds people whether they like it or not; international law binds states largely because they have consented to be bound.
Australia and international law
Australia is an active participant in international law, having signed and ratified many treaties. However, signing a treaty does not automatically make it part of Australian law. Under Australian constitutional principle, a treaty must be incorporated by an Act of the Commonwealth Parliament before it creates enforceable rights and duties inside Australia, which keeps the elected parliament in control of domestic law.
For exam answers, define international law, list its sources with treaties and custom emphasised, then draw the contrast with domestic law on the points of law-making, enforcement and jurisdiction.