 Because a treaty always results from the exchange of consent between the contracting parties, it is important that the consent of each of them be properly given. And in order for consent to be properly given, it must, on the one hand, be expressed by a competent organ to do so, and on the other hand, if competent, that organ must have given a real and informed consent. In this video, I shall only address the issue of the competence to express consent to treaties. The next video will deal with the issue of genuine and informed consent. The question of the competence to express the consent of the contracting state is a matter which is regulated under the domestic law of the state and under the internal rules of the organisation when the issue is the consent by an international organisation. However, states are not entitled to avail themselves of their domestic law provisions in order to escape their international law obligations. And as recalled by article 27 of the Vienna Convention that I quote, a party may not invoke the provisions of its internal law as justification for its failure to perform a treaty, end of quote. This is an axiomatic principle of international law, a principle without which international law would simply not exist. And this is easy to understand. If international law is indeed the result of the common will of states, in contrast domestic law is the result of the unilateral will of one state. Therefore, if a state were entitled in international law to avail itself of its own will in order to legally justify its failure to perform its international law commitments, such commitments could always be easily disregarded. And this would be legal under international law. International law would therefore shoot itself in the foot if it accepted that a state could decide not to obey international obligations for domestic law reasons. So, as a matter of principle, no domestic or internal rule can be used in order to defeat an international law obligation. However, there is one and only one exception to that principle. And this exception relates to the competence to express consent to a treaty. That only exception is to be found in article 46, paragraph one of the Vienna Convention, which reads as follows. A state may not invoke the fact that its consent to be bound by a treaty has been expressed in violation of a provision of its internal law regarding competence to conclude treaties as invalidating its consent, unless that violation was manifest and concerned a rule of its internal law of fundamental importance. End of quote. See how the provision is drafted. It starts from recalling the principle a state may not invoke the provision of its internal law. However, the provision states also the exception to that principle, together with the conditions to be met. And there are three conditions for the exception to be successful. One, the provision of internal law must be about the competence to conclude treaties and nothing else. However, two, not any internal law provision regarding the competence to conclude treaties can be invoked. It must be a provision which can be considered of fundamental importance. Additionally, three, the rule of domestic law about the competence to conclude treaties, which is of fundamental importance, must not only have been violated, but it must have been manifestly violated. It is only if all those three conditions are met that a state may rely on rules of its domestic law to escape its international treaty commitments by claiming its consent was not properly given. Paragraph 2 of article 46 of the Vienna Convention states that, I quote again, a violation is manifest if it would be objectively evident to any state conducting itself in the manner in accordance with normal practice and good faith. End of quote. In the Cameroon versus Nigeria case, discussing the validity of the maritime delimitation established by an agreement signed by the two heads of states, the court considered that constitutional rules concerning the authority to conclude treaties are indeed rules of fundamental importance. However, and because heads of states are presumed under article 7 paragraph 2 to have full powers and that this presumption is, as we have seen, substantive, the court added that, I quote, a limitation of a head of state's capacity in this respect is not manifest in the sense of article 46 paragraph 2 unless at least properly publicized. And because Nigeria never informed Cameroon of that rule, the court rejected Nigeria's claim, according to which its consent to the maritime delimitation agreement was not properly given. It is important to stress that in that case, the Nigerian constitution had changed several times following internal turmoil. And when the maritime delimitation agreement between the two heads of states was concluded in the mid 1970s, Nigeria was governed by the military. The government of Nigeria was under its constitution the supreme military council and the chair of that council, himself a member of the armed forces, was the head of state. According to the Nigerian constitution at the time, it was for the supreme military council rather than for the head of state to conclude treaties. So the head of state should have submitted the agreement to the supreme military council for having it approved. And this did not happen. However, the violation of such a constitutional provision was not considered by the court to be manifest because Nigeria did not properly inform Cameroon of the specificity of its constitution. And Cameroon had no obligation said the court to keep itself informed of the legislative and constitutional developments in Nigeria. So from this case, we can conclude that in order for its violation to be manifest, the domestic rule of fundamental importance about the competence to conclude treaties must have been made manifest to the other contracting party. The rule must have been manifested for its violation to be manifest.