On September 5th , 2018, it was the third training day of the first week of fourth training session of the China-AALCO Exchange and Research Program on international law’.

Mr. Santiago Villalpando, Chief of the Treaty Section, Office of Legal Affairs, United Nations, presented a wonderful speech entitled “International Treaty Law”. Professor Nie Jianqiang, deputy director of the Institute of International Law at Wuhan University, attended and presided over this speech.

In the morning session, Mr. Villalpando gave a brief introduction to the law of treaties. By comparing with the theoretical concepts of "contract" and "law" in domestic law, the concepts of the subject, effects and source of effects of the treaty are analyzed and further expanded. The source of international law, especially Article 38 of the Statute of the International Court of Justice, was detailed, interpreted and evaluated.

Then, based on the analogy of the novel, an outline of the milestones in the development of the Treaty Law, the Vienna Convention on the Law of Treaties was made, and the Convention was highly evaluated, and he held that the premise of any problem of law of treaty is the in-depth study of the Vienna Convention on the Law of treaties.

Finally, Mr. Villalpando gave an in-depth introduction to the functions of the Treaty Section of the United Nations Office of Legal Affairs, in particular the registration of treaties. The importance of the registration of treaties under Article 102 of the Charter of the United Nations is constantly emphasized, and the use of the United Nations Registered Treaty database is explained to participants through a live online display on the official website.

In the afternoon class, Mr. Villalpando continued his passionate and lively teaching methods, combining his personal experiences to explain the contents of the law of treaties in a simple way. He first pointed out that the study of treaty law is full of fun and should make good use of the provisions of the 1969 Vienna Convention on the Law of Treaties. In order to let the trainees experience how to solve the treaty issue in accordance with the Vienna Convention on the Law of Treaties, he guided the participants to learn the whole process of the treaty and its major difficulties based on the hypothetical case.

In this case, S is a substance produced by industry that is seriously harmful to the atmosphere. In order to protect the environment and limit the emission of S substances on a global scale, one country proposes to establish multilateral treaties within the UN framework, and other countries have supported them. Thus, the conclusion of the treaty work began. A number of meetings were held to discuss the specific content of the draft treaty, including the title of the treaty, the preamble, the main text, the final clause and the annex. Here, how the provisions are accepted. Mr. Villalpando emphasized the difference between Consensus and Unanimity. After a series of negotiations, it is followed by the signing, ratification and accession of the treaty. Treaty interpretation, retention and revision are also critical in the subsequent application process. With regard to the interpretation of the treaty, the Chief of Villalpando emphasized that, in his view, article 31 of the 1969 Convention on the Law of Treaties was a rule, with literal interpretation, contextual interpretation and interpretation of the purpose of the object as a whole. Whether the reservation to the treaty is valid or not is fundamentally judged whether it violates the purpose of the treaty.

The trainees listened carefully to Mr. Villalpando's class explanations, and also actively thought and answered questions in the classroom. They also raised questions about their participation in the legislative work, and reflected on their country's participation in international conventions or the status quo of the treaty. Mr. Villalpando also made clear and targeted reply.

Under the class, Mr. Villalpando communicated with the students humorously, causing the students to burst into applause.