In addition to the jurisprudence of individual nations, international law is the product of an elaborate system of norms and requirements. Hart argues that the international system has primary and secondary rules, which are mainly observed in practice. In this way, international law differs from national laws. In Hart’s view, international law is morally binding but not universal. However, it is not impossible to establish a rule that is universally binding.

Dworkin, for example, runs together the existence and legitimacy of international law. But this claim is problematic because it essentially implies that the existence of international law is indistinguishable from the legitimacy of national laws. Many people reject this view, and others disagree with Dworkin’s thesis that the rule of law is presumptively legitimate. But Follesdal argues that there is a conflict between legitimate rule of law and state sovereignty.

During the post-World War II era, the international architecture reached new heights. It claimed authority over diverse governmental matters, including the relationship between an individual and a state. It also widened its focus from national laws to cover issues of migration and the environment. The expansion of international law has led to an unprecedented growth in the complexity of legal issues. But despite its growing scope, it remains an area of contention. As such, lawyers are needed to stay abreast of current legal trends and challenges to international law.

One emerging area of international law is international criminal law. Traditionally, this area of international law has concerned itself with rules of law, including the need for fair warning before criminal behaviour is committed. However, the Nuremburg Trials illustrate the problems of fair warning and ask whether all grievous wrongs were criminally prohibited at the time the crimes were committed. In addition, international criminal law requires states to ensure that the punishments given are proportionate and justified.