 Article 10 of the Vienna Convention provides that, failing any other procedure or mechanism agreed by the parties participating in the drawing up of the treaty, the signature of the treaty establishes that the negotiated text is authentic and definitive. In other words, the end of the negotiations results from the signature of the treaty. Once the treaty is signed, its text is final, the draft treaty becomes the treaty. Treaties are usually identified by referring to the place and the date of their signature. For instance, the Convention on the Law of Treaties was signed in the city of Vienna on 23 May 1969. And aside from the authentication of the treaty, what are the other legal effects deriving from the signature of a treaty? Well the most important effect is that by signing a treaty, a state may express its consent to be bound by the treaty. However, this important effect does not automatically derive from the signature. As Article 12 of the Vienna Convention makes clear, the signature expresses the consent to be bound by the treaty only when the treaty provides that the signature shall have that effect or it is otherwise established that the negotiating parties were agreed that the signature would have such effect or again that the intention of the negotiating parties to give that effect to the signature appears from the full powers of the representatives involved or such intention was expressed during the negotiations. In other words, the signature expresses the consent to be bound by the treaty if that is the common intent of the negotiating parties. If they do not have such an intent, the signature cannot be considered as expressing the final consent to be bound by the treaty. And in such a case, a separate and distinct act will be needed to express such consent. That additional act is called the ratification of the treaty. The ratification may also be called the acceptance, approval or accession to the treaty. And in each case, and as the definition to be found in Article 2 of the Vienna Convention reads, it is an international act whereby a state or an international organisation establishes on the international plane its consent to be bound by the treaty. And it is important to stress that as Article 11 of the Vienna Convention makes clear, there is not one single means of expressing consent to be bound by a treaty. The contracting parties are free to decide for each treaty which one is to be preferred. As the International Court of Justice ruled in the Cameroon v. Nigeria case, I quote, both customary international law and the Vienna Convention on the Law of Treaties leave it completely up to states which procedure they want to follow end of quote. States may want the treaty to immediately enter into a force upon its signature and therefore considered that the signature is the act by which consent to be bound by the treaty is given. All states may prefer to give to themselves a moment of thought and evaluation and eventually also a moment of democratic approval at the national level so as to choose for a ratification process. When consent to be bound is not expressed by the signature of the treaty, the final closes of the treaty usually provide for the requirement of ratification and the procedure by which the treaty will take effect. In case of a bilateral treaty, the day when the instruments of ratifications of both parties are exchanged will usually be chosen as the day upon which the treaty will enter into force. In case of a multilateral treaty, the ratification by each party will take place at various moments in time but if this is so, when will the treaty take effect? When will it enter into force for each of the parties that have ratified it? Well most of the time parties agree that a certain number of ratifications are needed for the treaty to enter into force and this is because it simply makes no sense to have a treaty binding between only a few parties if it is a multilateral treaty. Hence in the final closes of the treaty you will most of the time find a provision entitled entry into force which states the conditions for such entry into force. It will take for instance article 84 of the Vienna Convention which requires 35 ratifications for the convention to enter into force. Furthermore, the same article states that the convention will enter into force 30 days after the 35th ratification. Before that day, 35 states have expressed their consent to be bound by the treaty but they are not yet bound by the treaty. Since that day arrives, the treaty enters into force which means it is legally binding on the states that have already ratified it. From that day and from that day only, the parties that have already ratified the treaty must perform it in good faith. Ratifications that are made after the day of the entry into force will usually produce their effect immediately or after a period of time specified under the treaty. In case of the Vienna Convention, that period is 30 days. The obligation to perform the treaty in good faith begins 30 days after each new ratification. In order to centralize that process and to keep all the interested parties duly informed of the various ratifications, the final closes of a multilateral treaty usually designate a depository with whom the instruments of ratifications must be deposited. For instance, article 82 of the Vienna Convention establishes the Secretary General of the United Nations as the depository of the instrument of ratifications of that treaty. Article 77 of the Vienna Convention defines what are the various administrative functions and duties that the depository must impartially perform. There is no need to go too much into details in that regard, but you may wish, of course, to read that provision for yourself. And of course when the signature of the treaty does not express the consent to be bound by the treaty, it must nevertheless entail the duty to respect the final closes by which the process of ratification and entry into force is provided for. And this is, of course, made clear by article 24, paragraph 4 of the Vienna Convention, and any other solution would not make sense. One more important legal obligation needs to be mentioned here, bending the entry into force of the treaty. During that period of time, awaiting that the treaty takes effect, each state or international organisation which has signed the treaty or expressed its consent to be bound by the treaty through ratification, each is obliged not to defeat the object and purpose of the treaty. And this is a general obligation, and it has been codified by article 18 of the Vienna Convention. It is an obligation, I quote, to refrain from acts which would defeat the object and purpose of the treaty. It is not an obligation to comply with the treaty, nor an obligation to perform any of its provisions. It is an obligation of good faith to abstain from any act which would make the object and purpose of the treaty meaningless. And it is an interim obligation. It only exists bending the entry into force of the treaty. And once the treaty enters into force and becomes binding, that obligation is replaced by the obligation to perform the treaty in good faith. Furthermore, the obligation not to defeat the object and purpose of the treaty exists until the signing party shall have made its intention clear not to become a party to the treaty. Hence a party which has signed a treaty and later decides not to ratify it can unilaterally free itself from that obligation by making clear that it does not intend to become a party to the treaty. From the moment such intention is made clear, the interim obligation stops to be binding and the state concern may perform acts which would run counter the object and purpose of the treaty. This has been a very long video. Well, please turn now to the exercise that follows to see how those concepts and obligations work in practice.