Nationalization of foreign property and deprivation of contractual rights have again achieved prominence through measures in Iran, Egypt, Indonesia, and, more recently, in Cuba. The end of certain regimes often brings with it changes in political and social conditions. And yet recognition of acquired rights is the principal basis of intercourse in economic relations, as recognized by the law of civilized nations. International law, far from being an outgrowth of only Western concepts, is indeed an expression of fundamental principles embodied in long established legal systems throughout the world. Islamic law, for instance, which is of real significance for one sixth of the world population, in the Middle East, Pakistan, Southeast Asia and parts of Africa, clearly embodies the universal maxim of the protection of acquired rights.
An anomalous situation arises where governments desire foreign investments while at the same time rights in property and contractual relations are threatened and even destroyed. The Brazilian Judge Levi Carneiro said in the Anglo-Iranian Oil Co. Case:
When there are so many countries in need of foreign capital for the development of their economy, it would not only be unjust, it would be a grave mistake to expose such capital, without restriction or guarantee, to the hazards of the legislation of countries in which such capital has been invested.