Classical liberals oppose to the Kantian cosmopolitanism on the ground that there is no need for a universal enforcer, separate nation states could realize this alone and together, since a universal enforcer itself would be a threat to liberty.

By the same token, classical liberals valued sovereignty of nations, and humanitarian intervention was not their concern. They believed that the developed countries could be models for less free countries through international trade and cultural exchange. States communicate and negotiate through diplomacy and this maintains the stability. In the Grotian view, diplomacy is the bond between members of international society that converge around common norms and goals that is international law (rule of law at international level). Due to the anarchical nature of the international system that lacks a central authority, international law is enforced by the states themselves and the different interpretations of rules may lead to conflicts. Generally, states recognize that it is in their interest to conform to international law. According to classical liberalism, international law must be restricted to the international protection of individual rights. This has been the ground for the establishment of the international governmental organizations since the nineteenth century.