Unratified Treaties, Unilateral Declarations and Modus Vivendi: Circumstances to be considered to have Effect on State Parties

Abstract

International law arises from the consent of states and state practice. The Vienna Convention on the Law of Treaties (VCLT, 1969) is an authoritative international document regarding treaties between and among states. The VCLT provides rules and guidelines concerning the conclusion,entry into force, reservations, interpretation, amendments, modification, invalidity, termination and suspension of the operation of treaties. In order to have binding effect, a treaty must fulfill the requirements provided under the VCLT. Some have argued that agreements that do not have a normative character, laying down specific legal obligations rather than simply asserting political positions, wishes or intentions, are not treaties. However, there is a fascinating tendency in international law to cite, as authoritative and even―binding, acts that have not been legally completed, despite the fact that the formalities of completion are explicit requisites for their legality. In the decisions of the Permanent Court of International Justice (PCIJ)and the International Court of Justice (ICJ), it is possible to observe that unratified agreements, unilateral statements (acts) of states, modus vivendiand other unperfected treaties are creating legally binding obligations. The Eastern Greenland and Nuclear Tests cases provide poignant examples.1 Solong as such decisions have their own impact on countries, and it is common to see that such treaties are used, it is important to study these court decisions. Nevertheless, concerns emanate from uncertainty over the conditions that must be fulfilled for unperfected agreements to have binding legal effect in the eyes of international courts; in other words, the question of when, how, and why certain unperfected treaties should be treated as binding is an important issue requiring clarification. In addition, it will provide a description for legal advisors in the Ministry of Foreign Affairs trying to predict whether or not such undertakings may create binding legal obligations.In fact, international courts do give justifications as to why they base their decisions on unperfected treaties. Therefore an attempt will be made to analyze these justifications. The author will look at the affirmative arguments and the counter-arguments concerning why unperfected treaties should be treated as binding or not.