- Treaties, bilateral and multilateral
- Customary international law
- From the practices of states undertaken in recognition of a legal obligation, must believe they are obliged to do something
- Can also be determined by examining authoritative statements made by countries
- For example of how it's determined, see Nuremberg Judgment (Lillich, p. 991)
- The law of war is to be found not only in treaties, but in the customs and practices of states which gradually obtained universal recognition, and from the general principles of justice applied by jurists and practised by military courts.
- This law is not static, but by continual adaptation follows the needs of a changing world.
What Forms International Law?
International Law consists of obligations resulting from: