Reserves and other one-sided declarations in the relation to international contracts

Although international law of the treaties has be­en benefiting for more than thirty years from its suc­cessful codification, the practice has revealed uncerta­inties and ambiguities with regard to implementation of some parts of the 1969 Vienna Convention on the Law of Treaties. This particularly relates to the regi­me of reservations where the law suffers from two key problems.

First, the Vienna Convention is silent on the qu­estion of other individual declarations than reservati­ons. The reticence appears to be especially detrimental to interpretative declarations. There is abundant prac­tice proving that States use interpretative declarations as widely as they do reservations. For a long time, reservations and interpretative declarations were not clearly distinguished in State practice or in doctrine. Nowadays, scholars as well as States recognize the di­fference between the two categories, a number of elements, however, help to blur the necessary distinctian: a) the terminology is hesitant, b] the practice of States and international organizatians is uncertain and c] the declatants' objectives are not always unambiguous.

Second, neither Article 19 nor any other provision of the Vienna Conventian makes clear how the per­missibility of a reservation shall be determined and what the consequences are of making an impermissi­ble reservation? The former question is particularly relevant in case of the reservation whase permissibi­lity is questionable for a possible cantradiction with the object and purpase of the treaty. Can the questi­on of allowance of such a reservation be solved by the way af acceptance and objections pursuant to Article 20 (4) and (5)? As regards the latter query, the care of the matter consists in evaluating the question whe­ther the invalidity of the reservation taints the entire acceptance of the treaty for the reserving State or the impermissible reservation can be severed from the act of acceptance.

In view of the aforementianed problems, the United Natians General Assembly autharized the UN Interna­tional Law Commission in 1993 to work out a guide to practice, which would take the form of draft articles whose provisians would be guidelines for the practice of States and international arganizatians in respect of reservations. The Internatianal Law Cammissian commenced its substantive work on the topic in 1995.

The purpase of the presented article is to analyze the results of the Commission's work up to now and ex­plain the essence of remaining problems, which are to be dealt with by the Commission in the near future.