Once the “popular plaything of Realpolitiker” the doctrine of rebus sic stantibus post the 1969 VCLT is often described as an objective rule by which, on grounds of equity and justice, a fundamental change of circumstances may be invoked as a ground for termination. Yet recent practice from States such as Ecuador, Russia, Denmark and the United Kingdom suggests that it is returning with a new livery. They point to an understanding based on vital States’ interests––a view popular among scholars such as Erich Kaufmann at the beginning of the last century.