Customary international law
Customary international law is an aspect of
Many governments accept in principle the existence of customary international law, although there are differing opinions as to what rules are contained in it.
In 1950, the
The International Court of Justice Statute defines customary international law in Article 38(1)(b) as "a general practice accepted as law". This is generally determined through two factors: the general practice of states and what states have accepted as law (
There are several kinds of customary international laws recognized by states. Some customary international laws rise to the level of jus cogens through acceptance by the international community as non-derogable rights, while other customary international law may simply be followed by a small group of states. States are typically bound by customary international law regardless of whether the states have codified these laws domestically or through treaties.
Jus cogens and customary international law are not interchangeable. All jus cogens are customary international law through their adoption by states, but not all customary international laws rise to the level of peremptory norms. States can deviate from customary international law by enacting treaties and conflicting laws, but jus cogens are non-derogable.