**International law** (also called public international law or the law of nations) differs fundamentally from domestic law because there is **no world government** with a central legislature, executive police force, or compulsory court system. It's a **decentralized** system based primarily on **consent** of sovereign states.
Here's a clear breakdown of who defines, drafts, agrees upon, and enforces international law:
### 1. Who Defines / Creates the Rules? (Sources of International Law)
The authoritative list of sources comes from **Article 38** of the **Statute of the International Court of Justice** (ICJ), which is widely accepted as the standard reference.
The main sources are:
- **International treaties / conventions** (most important in modern practice)
→ These are formal written agreements between states (or sometimes international organizations).
- **Customary international law**
→ Develops when states consistently behave in a certain way (**state practice**) and believe they are legally obligated to do so (**opinio juris**).
→ Once formed, it's binding on nearly all states (except persistent objectors during formation).
- **General principles of law** recognized by civilized nations
→ Basic legal ideas common to major domestic legal systems (e.g., good faith, estoppel, no one can be judge in their own case).
- **Subsidiary means** (to help interpret the above):
→ Judicial decisions (especially ICJ cases)
→ Writings of the most highly qualified scholars/publicists
In practice, **treaties** and **custom** are the two dominant ways new rules emerge.
### 2. Who Drafts and Agrees Upon Them?
- **Treaties**
→ Drafted through **negotiations** among states (often involving diplomats, legal experts, and sometimes international organizations like the UN).
→ Many multilateral treaties are negotiated in large conferences under UN auspices (e.g., UN Climate Change conferences, Law of the Sea Conference).
→ The **International Law Commission** (ILC — a UN body of legal experts) often drafts texts that later become treaties.
→ A treaty becomes binding only after states **expressly consent** — usually by signature + ratification (or accession). Only parties to the treaty are bound (pacta sunt servanda — "agreements must be kept" — is itself a fundamental customary rule).
- **Customary law**
→ Not "drafted" by anyone — it emerges **organically** over time from what states actually do and accept as obligatory.
→ No single vote or signature — it's proven through diplomatic correspondence, military manuals, national legislation, UN resolutions, etc.
In short: **States themselves** (through their governments) draft and agree to almost everything. No higher authority forces them.
### 3. Who Enforces International Law?
Enforcement is the weakest part — there is **no global police** or army that automatically enforces rules.
Enforcement relies on a mix of mechanisms:
- **Voluntary compliance** — most of the time states follow rules because it's in their interest (reputation, reciprocity, avoiding isolation, economic benefits, etc.).
- **Countermeasures & self-help** — injured states can impose sanctions, freeze assets, or (in extreme cases) use force in self-defense (UN Charter Art. 51).
- **United Nations Security Council** (UNSC)
→ The closest thing to a "central enforcer".
→ Under Chapter VII of the UN Charter, it can impose mandatory sanctions, authorize military action, or refer situations to the **International Criminal Court** (ICC).
→ However, any of the 5 permanent members (USA, Russia, China, France, UK) can **veto** decisions — making enforcement very political and selective.
- **International courts**
→ **ICJ** — settles disputes **between states** (jurisdiction requires consent; judgments are binding but enforcement often relies on UNSC or good faith).
→ **ICC** — prosecutes **individuals** for genocide, war crimes, crimes against humanity, aggression (jurisdiction via state consent or UNSC referral; relies on states to arrest suspects and enforce sentences — no own police).
- **Other pressures** — economic sanctions by coalitions of states, trade restrictions, diplomatic isolation, reputational damage, domestic political pressure, etc.
**Bottom line**: International law is **made and agreed to by states themselves** (mostly through treaties they voluntarily join), and **enforced mainly through political/diplomatic pressure, reciprocity, and — when it works — collective action via the UN Security Council**. Its effectiveness depends heavily on the willingness of powerful states to uphold it.
This is why people often say international law is "weak" compared to domestic law — but it still structures most of global relations surprisingly effectively on a day-to-day basis (trade, diplomacy, aviation, postal services, etc.). When major powers disagree or violate rules, enforcement becomes very difficult — which is exactly why the term gets "thrown around" so much in heated geopolitical debates.