414. The sources of international criminal law.

Like public international law generally, international criminal law has its formal sources principally in customary international law, treaties, and, as a subsidiary means for the determination of legal rules, international judicial decisions1.

A small number of categories of international crime, although a large number of specific international crimes, find embodiment in customary international law2, which also embodies general principles of international criminal responsibility3 and general defences to such responsibility4. Customary international law regulates too the rights and obligations of states in relation to the criminalisation of conduct under national law and the enforcement of that criminalisation5.

Many international crimes are created