If there is no world police force, why do countries obey international law?
Explain how international law is made, why states obey it, and how it is enforced.
How international law is created through treaties and custom, the reasons states comply with it, and the limited mechanisms available to enforce it.
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What this dot point is asking
This dot point asks you to explain three linked things: how international law comes into existence, why states actually follow it, and how it can be enforced when they do not.
How international law is made
There is no world parliament, so international law is created by states themselves in two main ways:
- By treaty: states negotiate and sign a treaty, then ratify it through their own domestic process. A treaty binds only the states that agree to it. Multilateral treaties such as the United Nations Charter are negotiated through international organisations and conferences.
- By custom: where states consistently behave in a certain way over time, believing they are legally obliged to (opinio juris), that practice can harden into binding customary international law that applies even to states that never signed a treaty.
Why states obey international law
Despite the lack of a world police force, states comply with international law most of the time. Reasons include:
- Consent: states are usually bound only by rules they have agreed to, so obligations reflect their own interests.
- Reciprocity: a state that breaks the rules cannot expect others to keep them, so mutual benefit encourages compliance, for example in trade and diplomacy.
- Reputation: states that breach their commitments lose trust, allies and influence.
- Pacta sunt servanda: the customary principle that agreements must be kept, which underpins the binding force of treaties.
- Order and stability: predictable rules benefit all states by reducing conflict and supporting commerce.
How international law is enforced
Enforcement is the weakest part of international law, because there is no central authority that can compel a sovereign state. The available mechanisms include:
- The United Nations: the Security Council can authorise measures, including economic sanctions or, in extreme cases, military action, although its permanent members can veto action.
- Sanctions: states or groups of states impose trade or financial restrictions to pressure a state into compliance.
- International courts and tribunals: the International Court of Justice resolves disputes between states that consent to its jurisdiction, and the International Criminal Court can prosecute individuals for serious crimes such as genocide.
- Diplomatic pressure: negotiation, condemnation and the withdrawal of recognition or cooperation.
These tools are uneven. They tend to work against weaker states and struggle to constrain powerful ones, especially the permanent members of the Security Council, who can veto any Security Council action against themselves or their allies. This is the structural reason enforcement is the weakest part of international law: there is no body that stands above sovereign states with the power to compel them, so compliance ultimately depends on consent and self-interest rather than coercion. The contrast with domestic law is the key analytical point, because in Australia police, courts and prisons can compel obedience from individuals, while no equivalent exists between nations.
For exam answers, separate the three parts clearly: how the law is made (treaty and custom), why it is obeyed (consent, reciprocity, reputation, order), and how it is enforced (United Nations, sanctions, courts, diplomacy), noting that enforcement is the system's main weakness.
Exam-style practice questions
Practice questions written in the style of TASC exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
TCE 20226 marksExplain two reasons why states obey international law despite the absence of a world police force.Show worked answer →
A 6 mark response needs two clear reasons, each explained, not just named.
Consent and self-interest. States are usually bound only by rules they have agreed to, so obligations reflect their own interests; reciprocity means a state that breaks the rules cannot expect others to keep them, which matters in trade and diplomacy.
Reputation. States that breach their commitments lose trust, allies and influence, so maintaining a good reputation encourages compliance.
Either could be replaced by pacta sunt servanda (agreements must be kept) or the value of a stable order. Markers reward two reasons properly explained, with the underlying point that compliance rests on self-interest rather than force.
TCE 202312 marksExplain how international law is made and enforced, and analyse why enforcement is the weakest part of the system.Show worked answer →
A 12 mark response needs how the law is made, the enforcement mechanisms, and an analysis of their weakness.
Made. Explain the two main ways: by treaty (states negotiate, sign and ratify, binding only those who agree) and by custom (consistent state practice carried out from a sense of legal obligation, opinio juris).
Enforced. Set out the mechanisms: the United Nations Security Council (sanctions, in extreme cases force), sanctions by states, international courts (the ICJ for disputes between consenting states, the ICC for individuals), and diplomatic pressure.
Analysis. Explain that enforcement is weak because there is no central authority that can compel a sovereign state; the Security Council's permanent members can veto action, and the tools work better against weaker states than powerful ones. Judge that international law is real and mostly obeyed, but its enforcement is far less reliable than domestic law. Markers reward a defended judgement on why enforcement is the system's main weakness.
