What is public international law?
"A body of legal rules that apply between sovereign states and other entities having international personality. Public international law, sometimes referred to as the `law of nations', differs from private international law which deals with the different municipal laws of different countries. Topics of public international law include: law of the sea; law of treaties; state jurisdiction; customary law; and the law of the (INT) Charter of the United Nations 1945. Through this body of law an attempt is made to clarify and codify the common interests of humanity. It is in practice identified and determined by its authoritative source: (INT) Statute of the International Court of Justice 1945 art 38."
Encyclopaedic Australian Legal Dictionary (LexisNexis AU)