"Universal values are created by means of contract. Treaties and customs [are] the two major sources of universal values. ...flexibility allows nations to modify or even repeal universal values. ...Peremptory norms of general international law, also known as jus cogens, share the attributes of "permanent" universal values. ...Universal Democracy does not embrace the notion that all universal values are timeless. ...even a peremptory norm can be modified."
January 1, 1970
https://en.wikiquote.org/wiki/Universal_value