The principle of non-retroactivity – a law would be retroactive if it ‘alters the status of legal acts that were performed before it came into existence’ 1 – is well established both in national and public international law. Within a domestic legal system geared towards respect of the rule of law, non-retroactivity primarily qualifies as a remedy to avoid the abuse of legislative power in the adoption of a law (eg, the retroactive infringement of individual rights and freedoms by the lawmaker) or the abuse of executive power in the application of this law (eg, the retroactive infringement of individual rights and freedoms by the executive/ administrative branch of government).3 Being aware of this principleoriented rule of law perspective, public international law – in particular treaty law (Article 28 of the Vienna Convention on the Law of Treaties 1969 (VCLT)) – has to consider the issue from another, but not completely different, angle. It must take into account that many of the most fundamental changes in the international legal order are treatydriven and thus result from conventional norms. In other words: treaties, entered into by equally sovereign States (Article 2(1) of the Charter of the United Nations 1945 (UNC)), are the most effective means of enabling public international law to meet the needs and expectations of the globalized world in the 21st century. Treaties, to some extent radically, change public international law pro futuro because the parties to the treaties have consented to henceforth accept and adjust to these changes. A general retroactive application of the treaties would go beyond that consent and, at least indirectly, carry the risk of imposing retroactive obligations on the individual.5 With regard to the latter point, the rule of law and the State consent-based dimensions of nonretroactivity go hand in hand. Article 28 VCLT, in addressing the temporal scope of a treaty, therefore reflects both: the traditional consentorientation of public international law as well as its more recently discussed attachment to a rule of law-based scheme of global governance.