How does international law operate and how does it interact with Australian law?
Analyse how international law is made and enforced and how it becomes part of Australian domestic law
A direct answer to the WACE Year 12 Politics and Law dot point on international law and Australia. Covers sources of international law, treaty-making, the external affairs power and domestic incorporation.
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What this dot point is asking
SCSA wants you to understand the nature and sources of international law, how it is made and enforced, and the specific Australian process by which international obligations enter domestic law. The recurring tension is between national sovereignty and international obligation.
The nature and sources of international law
International law is the body of rules governing relations between sovereign states and, increasingly, individuals and international organisations. Its sources, drawn from the Statute of the International Court of Justice, are treaties (express agreements between states), customary international law (general and consistent state practice accepted as law), general principles of law recognised by civilised nations, and, as subsidiary sources, judicial decisions and scholarly writing.
A key feature is that international law has no single sovereign legislature, no compulsory court, and no standing police force, so it differs fundamentally from domestic law. It relies heavily on state consent and reciprocity.
How international law is made and enforced
Treaties are made through negotiation, signature, ratification and entry into force. Enforcement mechanisms include diplomatic pressure, sanctions, dispute resolution by the International Court of Justice (which only has jurisdiction where states consent), and, for the most serious crimes, prosecution of individuals by the International Criminal Court. The UN Security Council can authorise binding measures, including sanctions or the use of force, but the veto held by its five permanent members frequently limits action. Enforcement is therefore the weakest element of international law.
Australia's treaty process
In Australia, the power to enter into treaties belongs to the executive (acting through the Governor-General on advice), reflecting the prerogative over foreign affairs. Since 1996, proposed treaties are tabled in parliament and examined by the Joint Standing Committee on Treaties before ratification, improving transparency, though parliament cannot itself ratify a treaty.
Incorporation into domestic law
Australia follows a dualist approach: international and domestic law are separate systems. Ratifying a treaty creates an obligation on Australia internationally, but it does not automatically change Australian law. To be enforceable in Australian courts, a treaty must be incorporated by Commonwealth legislation.
The Commonwealth usually relies on the external affairs power in section 51(xxix) of the Constitution to pass such laws. The High Court confirmed in the Tasmanian Dam Case (1983) that this power allows the Commonwealth to legislate to implement bona fide treaty obligations, even on subject matter that would otherwise be a residual state power. This significantly expanded Commonwealth legislative reach.
Even where a treaty is not incorporated, it can still influence Australian law indirectly. Courts may use it to help interpret ambiguous statutes, and in the Teoh case (1995) the High Court held that ratification could create a legitimate expectation that administrators would act consistently with the treaty, though later governments sought to limit that principle.
Evaluating the relationship
The dualist system protects parliamentary sovereignty by ensuring elected parliaments decide whether international obligations become enforceable domestic law. It also allows the Commonwealth to expand its powers through the external affairs power, which some see as eroding the federal balance. The relationship balances respect for international obligations against the protection of national sovereignty and the federal division of powers.
Exam-style practice questions
Practice questions written in the style of SCSA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
WACE 202112 marksAnalyse how international law is made and enforced and how a treaty becomes part of Australian domestic law.Show worked answer →
A 12 mark response needs the international process plus the Australian incorporation process.
Making and enforcing. International law comes from treaties, custom, general principles and subsidiary sources. It has no compulsory legislature, court or police; enforcement relies on consent, diplomacy, sanctions, the ICJ (which needs accepted jurisdiction) and the ICC, with the Security Council veto limiting action.
Australia's process. The executive negotiates, signs and ratifies treaties (since 1996 tabled and examined by the Joint Standing Committee on Treaties). Australia is dualist, so ratification binds Australia internationally but does not change domestic law.
Incorporation. A treaty becomes enforceable only when Parliament legislates, usually under the external affairs power (section 51(xxix)), confirmed in the Tasmanian Dam Case 1983. Unincorporated treaties can still aid statutory interpretation. Markers reward the dualist point and the external affairs link.
WACE 20236 marksExplain the difference between signing and ratifying a treaty, and why ratification does not automatically change Australian law.Show worked answer →
A 6 mark response needs the signature-ratification distinction and the dualist point.
Signature. Indicates Australia's intention to be bound and a commitment not to act against the treaty's purpose, but does not yet create binding obligations.
Ratification. The formal step by which Australia consents to be bound under international law, creating an international obligation.
Why no automatic change. Australia is dualist: international and domestic law are separate. A ratified treaty binds Australia internationally but must be incorporated by Commonwealth legislation (usually under the external affairs power) before it is enforceable in Australian courts. Markers reward the distinction and the dualist explanation.