Abstract

• The capacity of States to conclude treaties is the most important ground of their personalities. International Law recognizes that States may be able to become parties to treaties without accepting all of the provisions. Even though States excluded the legal effect of some provisions in the treaty, these States may become parties to the treaty with reservation clauses. States can adopt and apply the reservation, due to the increase in organizing countries and participation in treaties. Most international jurists said that reservations to international treaties are becoming more and more important at the present time. Reservations played an important role in the conclusion of treaties. In the law of treaties, the reservation process is a complex and difficult problem in the practice of States relating to concluding treaties. This research paper aims to understand the substances and the impact of reservations. This paper is a kind of doctrinal legal research, and it analyzes the statutory provisions, legal principles, and cases relating to reservation by using the qualitative method. States need to find out whether a treaty is serving the national interests of the State, to be aware of the treaty for verification, and to predict what may happen in the future as a result of the treaty. Moreover, States require knowing not only the objectives and principles but also the essence of each clause or provision before entering into a treaty. It is considered that these clauses or articles are consistent with the position of the State, not only the current situation, but also the long-term situation of the State. In order to achieve Goal 16 of the Sustainable Development Goals, this research expects to partly support strengthening the capacity of institutions and cooperating in international relations by concluding more treaties.