The article deals with Security Council Resolution 1540 (2004), of 28 April 2004. In it the Council, acting under Chapter VII of the Charter to keep weapons of mass destruction away from terrorists, imposed obligations on states. Brief observations on the concept of legislation are followed by comments on instances of near legislation by the Council and on Resolution 1373 (2001), of 28 September 2001, in which the Council, reacting under Chapter VII, and unanimously to the dreadful terrorist attacks of the 11th of that month, took measures fully comparable to legislation. Resolution 1373 (2001) imposed on states rules and principles already sanctioned by the General Assembly, which ties in with the lack of any trace of the preparatory work on the resolution, adopted so to speak instantaneously. In contrast, Resolution 1540 (2004), which imposed on states entirely new rules, arose from a protracted and officially mentioned process of private consultations leading to two open Security Council meetings, at which many states commented on the draft resolution under consideration, questioning its constitutionality and pointing to problems of interpretation and application it raised. Those issues, which did not prevent the unanimous adoption of Resolution 1540 (2004), are the main topic of the article.
