Article 38, Statute of the International Court of Justice
- Treaties
- Cannot use domestic law to get out of treaties
- Treaty supersedes custom
- Customary international law
- Interested States
- Must be fundamentally norm creating character
- When custom is found it applies to all states (State silence is consent)
- Persistent objector
- Excused from custom (only endorsed twice by ICJ and never only reason for excusing State from custom)
- Only during formation of custom
- Custom changes when contrary custom established
- New States abide by custom
General principles of law
Judicial decisions and teachings of publicists (subsidiary means)
Ex aequo et bono: take into account what is just and fair, and not bound by law (only if both States consent)