In international law, the term "jus cogens" (literally, "compelling law") refers to norms that command peremptory authority, superseding conflicting treaties and custom. The influential Restatement on Foreign Relations of the United States (Restatement) defines jus cogens to include, at a minimum, the prohibitions against genocide; slavery or slave trade; murder or disappearance of individuals; torture or other cruel, inhuman, or degrading treatment or punishment; prolonged arbitrary detention; systematic racial discrimination; and "the principles of the United Nations Charter prohibiting the use of force." Jus cogens norms are considered peremptory in the sense that they are mandatory, do not admit derogation, and can be modified only by general international norms of equivalent authority.
Evan J. Criddle & Evan Fox-Decent,
A Fiduciary Theory of Jus Cogens,
Yale J. Int'l L.
Available at: https://digitalcommons.law.yale.edu/yjil/vol34/iss2/3