EFECTO DEL PROCESO DE SALMUERADO

The idea of customary law as being represented by a tacit pact was first expressed by the Roman Jurisconsults.^^ During the classic period of international law, some leading writers, such as Vitoria, Wolff and Vattel also espoused this view.^^ Since then, more refined views have been developed along those lines. It has to be observed, however, that some slight variations may be found in the way some contemporary writers have expounded it. One of such writers is Prof. Anzilotti, whose view may be summarized as follows. He first sets out a fimdamental premise: that States are sovereign entities, and therefore an international legal norm cannot be created except by means of an agreement between equals.^ ^ He then points out that the type of agreement which gives rise to a customary rule assumes a tacit form.^^

One is never sure as to whether by tacit agreement Prof. Anzilotti meant a species of treaty or simply an agreement latu sensu, that is, a consensus or coincidence of wills. None the less, as the binding force of both the tacit agreement and the express agreement was said by Anzilotti to rest on the same rule, pacta sunt servanda, one is led to believe that he referred to custom as

a mere species of treaty.^^ If such interpretation is correct, then there would be no difference between a custom and an informal treaty. That seems to be a great dilemma for all those who advocate the tacit agreement view. One could firstly ask why attribute a different name to custom given that it does not represent a distinct category. Secondly, if custom is a type of treaty, it would follow that those rules generally applicable to treaties - regarding their formation, operation, termination, and so forth - would be equally applicable to custom.^

Considering, in particular, some general rules which deal with State consent in a treaty process, they are clearly inapplicable to the customary process. For instance, in a treaty process, only specific persons who have or are supposed to have full powers may qualify as a State's representative for the purpose of expressing the consent of this State to be bound by a treaty.35 Having regard to this condition. Prof. Strupp has put forward the view that only those organs which, according to the internal legal order, can express a State's consent to be bound by a treaty, may manifest a State's will or consent in the customary process.^^ Anzilotti made no such explicit statement, but he plainly discarded organs which perform solely internal acts (as opposed to international acts) from the list of those organs whose acts may reflect a State's will or consent regarding a given tacit agreemenL^^ As it is explained in more detail in Chapter IV, there is an overwhelming body of State and judicial practice, not to mention doctrine, which holds a broader view on this question, conceding the possibility that any organ or agent from the three main branches of the State may - without the need for special powers - participate in the customary process.^^ Furthermore, it is very questionable whether consent in the customary process would be really expressed in the same way as consent is expressed in a treaty process, that is, by a single and definite a ct If there is no formal act in the customary process whereby a State's consent is given, there is no need for representatives vested with special powers. Thus, the rule regarding legal capacity of State organs or agents to convey a State's consent to be bound by a treaty seems to be inapplicable to the customary process.

If this idea of custom as a species of treaty is pursued further, it should also be possible for a State to invoke the application of rules which establish general grounds for the invalidity of consent Thus, factors such as error, fraud, coercion, corruption of a representative, and lack of authority of a representative could be deemed to vitiate consent to a customary rule.^^ Again, the nature of the customary process seems to explain the fact that there is no evidence that this possibility has ever been realized in practice. The last two factors, which refer to a State's representative in the exercise of his function, can be dismissed on the ground that the expression of consent in the customary process does not seem to require a single competent representative for the accomplishment of a single a c t Fraud and error, however, are not theoretically inconceivable.^ A State may plead error, for instance, in acquiescing in, or consenting to a legal claim (or the situation created by it) of another State. But the plea of error regarding an on-going general practice, as opposed to the practice of a particular State, would seem inadmissible. Otherwise, one would be accepting the (absurd) possibility that the same State could have consented in error to every claim and practice which forms the general practice. Therefore, unless one is referring to a bilateral custom, error and fraud in consent would seem to be inapplicable to the case of a general custom. The very fact that there is no known case where a State has invoked any such grounds as invalidating its previous consent to a customary rule attests that they are inappropriate to the case of customs.

The idea of custom as a tacit agreement would introduce an element of uncertainty into the legal relations of the States bound by a custom. So far as State consent in the customary process is considered to be tacit, the stability of the 'agreement* would be seriously weakened, since a tacit manifestation can be more easily denied by the State who is supposed to have expressed i t

The tacit agreement theory, when interpreted in the sense that custom is a type of treaty, would indicate that a general custom could only be formed in either of the following ways: l)as the aggregate of a number of similar bilateral agreements or 2)originally as a bilateral agreement open to all States, which progressively extends the number of States parties to i t

The second description would seem to be more reasonable, since a State's consent to an international practice can only be vis-à-vis all States, i.e., erga omnes. In other words, when a State is consenting to a general customary rule, it knows that the number of States involved in the international practice may enlarge and in fact it desires that the practice be generally established in this way. On the other hand, there is not a shred of evidence that States engage in an international practice and express their consent to it with a view to forming, acceding to or entering into a type of multilateral agreement

This model of a (general) customary process presumably presents the same normative range of a multilateral treaty process: the scope ratione personae of the resulting general customary rule should be limited to those States which actually consented to i t One should bear in mind that if custom is to be seen as a type of treaty. States are only bound by it if they have rirst consented to i t and in Anzilotti's view, this consent is tacitly manifested. If this were the case, then the Court should apply a particular custom to a case only after it has satisfied itself that both parties to the case had at some point in the past consented to the rule. However, as Chapter IV demonstrates, this has not been the procedure adopted by the Court. Moreover, the analysis of the drafting history of Art 38 (2) of the PCITs Statute has shown that the Drafting Committee clearly rejected a definition of custom which required the need for the consent of the States before a custom could be applied to them.^^ Another bar to this model of a general customary process is that general customs may apply to States which could never have consented to them, either for lack of interest or lack of opportunity. One wonders whether Anzilotti could not have had recourse to the analogy of an objective regime established by a treaty. Had he done so, then he might have been able to explain how a general custom (as a type of multilateral treaty) would be applicable to some States regardless of their will. But that approach would still require the definition of an objective treaty, and the determination of how far it would really resemble a custom. Perhaps the fact that he and other voluntarists have not considered this option attests to its lack of cogency.

It has to be admitted, however, that there is some consensus in the doctrine - and the Court's practice may be interpreted as endorsing it - to the effect that the scope ratione personae of bilateral and sectional customs is really limited to the States which participate in them/^ But the sole fact that the Court envisaged a limited scope ratione personae for such types of custom does not justify or explain the conclusion that it sanctioned the tacit pact theory in those cases.

In contrast with the indications given by Anzilotti as to the conventional nature* of custom (contradictory though as it may seem), he made a distinction between custom and treaty in the following way: while a tacit agreement is an 'spontaneous* and 'almost unconscious' manifestation of certain necessities arising out of a common life, a treaty presupposes a voluntary co-operation', a more developed conscience* of the necessities of the collectivity.^^ If anything, this distinction adds to the confusion between both terms, for if treaty is the genus and custom the species, then custom could not lack an essential quality of treaty, namely, its voluntary and conscious character. Indeed, it is difficult to conceive how an agreement could arise from an unconscious and spontaneous manifestation. This also throws some doubt as to whether a tacit agreement latu sensu is feasible, unless the spontaneous manifestations meet each other *by chance'. Consent is necessarily a voluntary and conscious act, which means that in propounding that distinction Anzilotti seems to negate the very basis of his theory, namely, the voluntary character of the customary process.

It should be noted, finally, that Anzilotti also makes clear that it is not a State's will or consent that produces law-creating effects but rather the law which attaches such effects whenever this will or consent is manifested.^

Another account of the tacit agreement doctrine was given by Prof. Tunkin.^^ He defined consent* and recognition' in the same way, namely, as the expression of a State's will to consider a particular customary rule as a norm of international law .^ He also added that the bonds between a State accepting a customary norm of international law and other States who

already have recognized this norm are basically identical with those bounds established among States with the aid of an international treaty'/^

It is noteworthy, firstly, that Tunkin also defined opinio juris in the same way: 'Opinio juris

signifies that a State regards a particular customary rule as a norm of international law, as a rule binding on the international plane. This is an expression of the will of a State, in a way a proposal to other States'.^ Thus, he put consent as synonymous with the subjective element, both meaning that a State 'considers a customary rule as a norm of international law', and both being the expression of a State's will. The question that needs to be addressed is why should one have two concepts (or three, if one takes into account the term recognition') to convey the same idea. Perhaps this was a compromise, dictated by a dilemma which can be described as follows: if opinio juris were to be discarded altogether, then Tunkin would be isolated in the face of a settled view in doctrine and in the case law of the Court to the effect that this element is necessary for the definition of a customary rule; on the other hand, the idea of dismissing the concept of consent in the customary process would be inconceivable for Tunkin.

In addition to using those two concepts interchangeably, Tunkin brought in another source of confusion. It has already been pointed out that, in Tunkin's view, both consent and opinio juris spring from a State's will. After defining opinio juris in this way, he added that when

other States also express their will in the same direction, a tacit agreement is formed with regard to recognizing a customary rule as an international legal norm'.^^ Given that this 'co­ ordination of wills' as expressed in a tacit agreement aims, in Tunkin's opinion, at the

recognition of a certain rule of conduct as a norm of international law' (which, it should be recalled, is precisely the definition assigned by him to opinio juris and consent) it would follow that: \)opinio juris and/or consent would be the object of a tacit agreement resulting from the co-ordination of at least two States' wills; 2)this tacit agreement would therefore represent an agreement to do something, namely, to consent or to hold an opinio jurist in other words, it is an agreement to recognize a given 'customary rule' related to an usage as a norm of international law. The first point to be made about this view is that it offers no definite

conclusion as to what brings about a customary rule: is it the (tacit) agreement itself, the act of recognition, opinio juris, consent, or the original will to agree (either in isolation or in conjunction with the other State's will)? The answer might be found in the view that they are all relevant and part of the customary process which, according to Tunkin's framework, could be described as follows:

usage > co-ordination of wills > tacit agreement > consent or opinio juris or recognition > customary rule

This description, however, may leave the wrong impression that each element corresponds to a separate period in time, whereas, for instance, it would be very difficult to distinguish between consent and the co-ordination of wills from a time perspective. In addition, given that consent is mostly tacitly manifested, and therefore it is to be inferred from practice (or usage), should not practice and consent be viewed as a single phenomenon or simultaneous?

Tunkin's view does not seem to employ the term recognition' in its ordinary sense, that is, as an act of identiHcation of something which already exists. He seems to suggest that without State recognition (consent or opinio juris) there could not be a customary rule but an usage only. Therefore, he envisages recognition' as a type of constitutive act, an act which brings about the customary rule. If, however, this term were to be used in its proper sense, then recognition of a customary rule (which, in Tunkin's view, represents also opinio juris or consent) should, by logic, constitute a mere admission of the existence of such rule, and the element which brought about that customary rule should be looked for elsewhere.^^ The main difficulty about the meaning attributed by Tunkin to the act of recognition is that, being constitutive in character, recognition should be express and not assumed to happen in such a general and widespread way, as in the case of a general custom. This form of describing consent (i.e., recognition) resembles Rousseau's hypothesis of a general consent to a social contract As a direct result of this theoretical exercise, recognition may be assumed, presumed or alleged even in situations where a State did not have any occasion for or interest in

manifesting its position regarding a given international practice.^ ^ The very fact that every State is not required to prove its prior (tacit) recognition of a general customary rule bears witness to the hypothetical character of this view.

Tunkin also leaves no very clear indication concerning the nature of the tacit agreement leading to a customary rule, but it seems possible to arrive at an interpretation. On the one hand, he has pointed out that the bonds between the States parties to a tacit agreement are 'basically identical' with those established by a treaty. On the other hand, he has stated that the expression tacit agreement' is 'somewhat misleading as it may be interpreted as meaning that in this case the process is the same as in the case of the treaty process, whereas the customary process is a specifîc process of norm-creating'.^^ From those two assertions one can conclude that in Tunkin's view: l)custom and treaty share the same binding force or normative quality; 2)custom is a different legal process, and therefore its product, a customary rule, is distinct from a treaty rule. As to the binding force, he would perhaps be clearer if he said that both the customary norm and the conventional norm share the same normative quality simply because they are legal norms. With regard to the distinctiveness of the customary process, it can only mean that by tacit agreement' Tunkin was referring to a mere 'coincidence of wills', and not to a tacit agreement in the sense of an informal treaty. Thus, the expression co-ordination of wills' would also seem inadequate, for it may mislead the reader into thinking that the customary process is not the result of a mere convergence of wills but rather of a purposeful act of a conventional nature.

n.

The examination of the main consensualist theories above seems to lead to the conclusion that State consent or will alone is unable to explain its own validity or its law-creating (or normative) force. It has also unravelled some inconsistencies in those theories which affect the very concept of consent in the customary process as adopted by them. It can be argued that it is irrelevant whether there is some superior rule or principle which determines that the manifestation of State consent produces normative effects, for even if consent is only a step in

a law-creating procedure, the fact remains that consent is necessary and indeed essential for