Judgment of 25 September 1997
The case arose out of the signature, on 16 September 1977, by the Hungarian People's Republic and the Czechoslovak People's Republic, of a treaty concerning the construction and operation of the Gabcíkovo-Nagymaros system of locks in order to further the utilization of the natural resources of the Bratislava-Budapest section of the Danube river. The project was essentially aimed at the production of hydroelectricity, the improvement of navigation on the relevant section of the Danube and the protection of the areas along the banks against flooding. It provided for the building of two series of locks, one at Gabcíkovo (in Czechoslovak territory) and the other at Nagymaros (in Hungarian territory), to constitute a single and indivisible operational system of works.
As a result of intense criticism which the project had generated in Hungary, the Hungarian Government decided on 13 May 1989 to suspend the works at Nagymaros pending the completion of various studies. In October 1989, Hungary decided to not continue the work any further.
During this period, negotiations took place between the parties. Czechoslovakia also started investigating alternative solutions. One of them, an alternative solution subsequently known as "Variant C", entailed a unilateral diversion of the Danube by Czechoslovakia on its territory. On 23 July 1991, the Slovak Government decided to begin construction to put the Gabcíkovo Project into operation by the above-mentioned alternative solution.
On 19 May 1992, the Hungarian Government transmitted to the Czechoslovak Government a note verbale unilaterally terminating the 1977 Treaty with effect from 25 May 1992. On 15 October 1992, Czechoslovakia began work to enable the Danube to be closed and, starting on 23 October, proceeded to the damming of the river, before Slovakia became an independent State on 1 January 1993.
Slovakia and Hungary then concluded in April 1993 a compromis, inter alia requesting the Court to decide whether the Republic of Hungary had been entitled to suspend and subsequently abandon, in 1989, the works on the project.
In its judgment of 25 September 1997, the Court started by taking the view that in many respects the provisions of the Vienna Convention concerning the termination and the suspension of the operation of treaties, set forth in its Articles 60 to 62, are to be considered as a codification of customary international law. It then found that in suspending and subsequently abandoning the works for which it was still responsible Hungary had expressed its unwillingness to comply with at least some of the provisions of the Treaty of 1977, the effect of which was to render impossible the accomplishment of the system of works that the Treaty expressly described as single and indivisible.
The Court further considered that the state of necessity is a ground recognized by customary international law for precluding the wrongfulness of an act not in conformity with an international obligation. It also considered, moreover, that such ground for precluding wrongfulness can only be accepted on an exceptional basis. It acknowledged that the concerns expressed by Hungary for its natural environment in the region related to an essential interest, but that the perils invoked by Hungary, without prejudging their possible gravity, were not sufficiently established in 1989, nor had they been imminent; and that Hungary had had available to it at that time means of responding to these perceived perils other than the suspension and abandonment of works with which it had been entrusted.
The Court also noted that Hungary - when it decided to conclude the 1977 Treaty had been presumably aware of the situation as then known; and that the need to ensure the protection of the environment had not escaped the parties. The Court therefore concluded that, even if it had been established that there was, in 1989, a state of necessity linked to the performance of the 1977 Treaty, Hungary would not have been permitted to rely upon that state of necessity in order to justify its failure to comply with its treaty obligations, as it had helped to bring it about. In the light of the conclusions reached above, the Court found that Hungary had not been entitled to suspend and subsequently abandon the works for which it was responsible.
As to the question whether the Czech and Slovak Federal Republic had been entitled to proceed, in November 1991, to the provisional solution and to put into operation from October 1992 this system, the Court observed that the basic characteristic of the 1977 Treaty was to provide for the construction of the system of locks as a joint investment constituting a single and indivisible operational system of works. The Court accordingly concluded that Czechoslovakia, in unilaterally putting Variant C into operation, was not applying the 1977 Treaty but, on the contrary, violated certain of its express provisions, and, in so doing, had committed an internationally wrongful act.
As to the legal effects of the notification of the termination of the Treaty by the Republic of Hungary, the Court first observed that, even if a state of necessity is found to exist, it is not a ground for the termination of a treaty but may be only invoked to exonerate from its responsibility a State which has failed to implement a treaty.
Besides, in the Court's view, the prevailing political conditions had not been so closely linked to the object and purpose of the Treaty that they constituted an essential basis of the consent of the parties and, in changing, therefore did not radically alter the extent of the obligations still to be performed. The changed circumstances advanced by Hungary had thus, in the Court's view, not been of such a nature that their effect would radically transform the extent of the obligations still to be performed in order to accomplish the project.
While reiterating that Czechoslovakia had violated the treaty when it diverted the waters of the Danube, the Court found that it had not yet done so when constructing the works which eventually led to the putting into operation of Variant C. In the Court's view, therefore, the notification of termination by Hungary on 19 May 1992 had been premature and Hungary had thus not been entitled to invoke any such breach of the treaty as a ground for terminating it when it did.
Finally, the Court took the view that although it had found that both Hungary and Czechoslovakia had failed to comply with their obligations under the 1977 Treaty, this reciprocal wrongful conduct did not bring the Treaty to an end nor did it justify its termination.
In the light of these conclusions, the Court found that the notification of termination by Hungary of 19 May 1992 did not have the legal effect of terminating the 1977 Treaty.
As to the question whether Slovakia had become a party to the 1977 Treaty as a successor State of Czechoslovakia, the Court referred to the principle that treaties of a territorial character remain unaffected by a succession of States, a principle which, according to the Court, is part of customary international law. The Court accordingly concluded that the Treaty itself had not been affected by a succession of States and had thus become binding upon Slovakia on 1 January 1993.
As to the legal consequences of the judgment, the Court observed that the 1977 Treaty was still in force and consequently primarily governed the relationship between the Parties. Taking into account the fact, however, that the Treaty had not been fully implemented by either party for years, it considered that the factual situation as it had developed since 1989 was to be placed within the context of the preserved and developing treaty relationship, in order to achieve its object and purpose in so far as that is feasible.
President Schwebel and Judge Rezek appended declarations to the judgment while Judges Weeramantry, Bedjaoui and Koroma all appended separate opinions. Finally, Judges Oda, Ranjeva, Herzegh, Fleischhauer, Vereshetin and Parra-Aranguren and Judge ad hoc Skubiszewski appended dissenting opinions.
On September 3, 1998, Slovakia, on the basis of Article 5 (3) of the Special Agreement, filed a request for an additional judgment in the case, such an additional judgment being necessary, according to Slovakia, because of the unwillingness of Hungary to implement the Judgment delivered by the Court. At the moment of writing, this item was still under negotiations between the Parties; no formal act having been taken by the Court.