The lives of the doctrine of peremptory norms (jus cogens) in international law

The doctrine of peremptory norms of general international law (jus cogens) was reflected in the Vienna Convention on the Law of Treaties (VCLT) more than half a century ago and is considered by scholars to be one of the most controversial phenomena of modern international law. Currently it is unclear how exactly peremptory norms appear, and who proclaims their jus cogens status and at what point. Despite many publications, the inclusion of jus cogens doctrine in the text of the VCLT and in the ILC Draft conclusions on identification and legal consequences of peremptory norms of general international law of 2022 (ILC Draft conclusions), the nature, content and legal effect of jus cogens remains unconvincingly formulated and therefore controversial, while the doctrine itself has reached its limits with quite scarce practical results. The contradictory attitude of States towards the doctrine of jus cogens, when they verbally support this doctrine but do not apply it in practice, rather indicates its rhetorical value and the absence of any practical value. In turn, the lack of practice and the desire of States to develop such practice raises the issue of the normative meaning of the doctrine. Despite the expectations caused by the return of the ILC to the issue of jus cogens in the second decade of the 21st century, the Draft Conclusions developed by the Commission have already caused reasonable complaints due to the lack of clarity regarding the requirements under which the norm acquires the status of jus cogens. The developed ILC methodology for identifying such norms with the need to find convincing evidence of double opinio juris looks difficult to implement in practice. In addition, the methodology is radically at odds with the approach of international courts which tend to declare the existence of such peremptory norms without any justification. Because of this, it is very likely that the Draft Conclusions of the ILC will be ignored by the courts and States in terms of the methodology for identifying jus cogens, which casts doubt on the value of the Commission’s work in this regard.