(1) A rule of international law is one that has been accepted as such by the international community of states
(a) in the form of customary law;
(b) by international agreement; or
(c) by derivation from general principles common to the major legal systems of the world.

(2) Customary international law results from a general and consistent practice of states followed by them from a sense of legal obligation.

(3) International agreements create law for the states parties thereto and may lead to the creation of customary international law when such agreements are intended for adherence by states generally and are in fact widely accepted.

(4) General principles common to the major legal systems, even if not incorporated or reflected in customary law or international agreement, may be invoked as supplementary rules of international law where appropriate