The consensual theory

The basic tenet of the consensual theory is that the binding quality of international law - its existence as Taw' - flows from the consent of states. It is said to be a 'posi-tivistic' system of law based on the actual practice of states. In its pure form, this consensual or positivist theory stipulates that no international law can be created without the consent of the state which is to be bound. Thus, 'new' states would not be bound by pre-existing rules because consent is the source of all legal obligations. International law is said to flow from the will of the state. It is formed from the real­ities of international life rather than its desirabilities. It is created by what actually goes on (consent), rather than according to some higher moral principles.

This theory recognises that a state's consent may be given in a variety of ways -express in treaties or implied in custom - but essentially the system of international law is based on voluntary self-restriction. In this regard, the consensual theory has certain attractions, for it appears to reflect accurately what goes on in international society. The rule that states are bound by their treaty obligations {pacta sunt servanda -treaties must be observed) seems to be based on consent because, as we shall see, treaties are generally binding on a state only if it deliberately and positively accepts the terms. Similarly, it is not inconceivable to regard customary law as being con­sensual, for consistent state practice may be tantamount to agreeing to be bound by the rule that then develops.

However, there are certain difficulties with the consensual approach to inter­national law, both theoretical and practical. First, as a matter of legal theory, it is not at all clear why states can be bound only by self-imposed obligations. There seems to be no necessary reason why this should be so, especially since many rules are not really referable to consent. Indeed, if there exists a rule that says 'states can create law only by consent', where did that rule come from? Where is the legal authority for the pacta sunt servanda)'consent rule? If we say that states have always behaved as if consent was fundamental to the creation of legal norms, we can ask further why it is that customary practice should have the authority to validate legal rules? In fact, the search for the legal source of the consent rule can go on ad infinitum, for we can always ask one more question and take one more step up the 'ladder of authority'.

Second, on a practical level, consent does not explain the existence of all legal obligations. The last 25 years have witnessed the birth of many 'new' states, includ­ing former dependencies of colonial powers and former members of defunct feder­ations (Yugoslavia, USSR). If consent is the basis of international law, how is it that

The nature of international law and the international system

these new states are bound by pre-existing rules of customary law? There is no doubt that they are bound by the general obligations of international law, yet they have not had the opportunity to accept or reject them. It has been suggested that consent for new states is implied, either specifically by their 'first act' of state prac­tice under an existing rule, or generally by acceptance of membership of the inter­national community. This is, however, no more than a fiction, since it would allow states to 'opt out' of certain rules if the intention not to be bound was made known. This simply does not happen. To talk of consent in such circumstances is unrealis­tic and ignores the pre-existing validity of international law for new states. Similarly, a change in circumstances may expose an existing state to rules of cus­tomary law with which previously it was unconcerned, yet it is still bound without its prior consent. For example, Panama and Liberia did not have the chance of objecting to customary maritime law before they became influential maritime states. In fact, even the binding quality of the ultimate consensual instrument - the treaty - cannot be explained fully by use of the consent theory. There is, for example, a limited class of treaties, known as dispositive treaties, which are mainly concerned with territorial issues and which bind all states. After the UK ceded to China by treaty in 1997 that part of the Hong Kong colony which was sovereign UK territory, no other state claimed (or could claim) that the UK was still the sovereign by alleging that they were not a party to the UK/China bilateral treaty. Other states have not consented to this transfer of jurisdiction but they are bound by it. More importantly, there are certain fundamental rules of customary law (rules of jus cogens) which cannot be altered by the express agreement of states, even if in treaty form. If consent was the basis of international law, nothing would be unalterable by treaty.

In general, then, the consensual theory is attractive but it does not describe accur­ately the reality of international law. When we consider the sources of international law in Chapter 2, it will become apparent that consent is a method for creating binding rules of law, rather than the reason why they are binding.

Date: 2014-12-21; view: 3549