CUSTOMARY INTERNATIONAL LAW



Customary International Law

Customary International Law

Introduction

Perhaps the most important source of international law is custom — more commonly referred to as “customary international laws. The “state practice” element requires a significant amount of countries behaving in certain. There cannot be a rule of customary international law that most states do not actually follow or observe in the course of their actions. Element requires that the acts and behaviours of the state practice stems from a sense of legal obligation. States just behaving in a certain way is not enough. They must be doing so out of a belief and sense that it is their legal obligation to behave in that way. In many cases, it must simply be inferred from the uniformity and constancy of state conduct. When states are in agreement about the rule, then less stringent evidence of their sense of legal obligation is required. In order to understand the status of the precautionary principle in the international law, one needs to explain the status of that law itself. I will try to answer the question of what is the customary international law and what are the criteria for the rule to become a part of customary international law.

State Practice of the Rule of Law

The traditional doctrine explaining the customary international rules claim that a mere fact of consistent international practice is not enough to create a rule of law in the sense of the practice. Hence an additional element is required. Customary rules result from the combination of two elements: “an established, widespread, and consistent practice on the part of States; and a psychological element known as the opinio juris sive necessitatis (opinion as to law or necessity). Very good example on this point is the ICJ judgment in the North Sea Continental Shelf case where the process by which a treaty provision might generate a rule of customary law is discussed (Schwarzberger, 1995). It reads from the judgment of this case that “not only must the acts concerned amount to a settled practice, but they must also be such, or be carried out in such a way, as to be evidence of a belief that this practice is rendered obligatory by the existence of a rule of law requiring it. The need for such a belief, i.e., the existence of a subjective element, is implicit in the very notion of the opinio juris sive necessitates (Rosalyn Higgins, 1994).

In this point the paradox is being reached where the implication suggests that in order for the rule to constitute customary law such rule must be practiced by the States. Hence, the question arises of how a state practices such rule which is not a rule of customary law before it does so. It is known that the precautionary principle is widely applied within the domestic levels of legislation. It has become a part of the European Union's legislative process with regards to Customary international laws (Robert Jennings and Arthur Watts, ...