At international level, refers to binding rules deriving from international treaties that are in force, as well as national legislation. Customary law and general principles of law recognised by States [ICJ Statute arts 38(1)(b) and (c) respectively] are also legally binding. Environmental law includes a wide spectrum of so-called ‘hard law’ instruments, such as international treaties and national and sub-national legislation, as opposed to soft law instruments. The distinction between soft and hard law is not always clear and/or helpful, and the so called ‘soft law’ instruments can still have hard-law type of consequences. Soft-law instruments are not law in the sense used by Article 38(1) of the ICJ Statute, but they are usually negotiated and drafted with care, sometimes in great detail, and are intended in many cases to have normative significance despite their non-binding, non-treaty form. See Alan Boyle and Catherine Redgwell, International Law and the Environment (4th edition), 2021, p. 35.