Chicago Journal of International Law
One keg similarity between natural law and international law is that they seek to obtain a stable social order without the intervention of any state authority capable of issuing and enforcing its commands to those subject to its rule. Among ordinary individuals in a state of nature that weakness tends to lead to a stripped-down libertarian regime that features simple rules of acquisition, contract, and protection. The system gains its relative stability from the brute fact that between rough equals the part in the defensive posture will win out, so that great disparities in power are needed to disrupt the basic equilibrium. Similar constraints apply to nations in international affairs. Only within sovereign states is it possible to seek (but not necessarily to obtain) gains from the use of taxation or eminent domain powers. The dangers implicit in the use of these powers caution against the adoption of strong centralized forces in international affairs, where the risks of misapplied power are likely to outweigh the possible gains from greater centralization of political power in international organizations.
Richard A. Epstein, "The Natural Law Bridge between Private Law and Public International Law," 13 Chicago Journal of International Law 47 (2012).