Interpretation

As Anzilotti emphasized in 1912,² in the past there were no binding rules on interpretation. The criteria for construing treaty law were merely 'rules of logic', borrowed from national law or developed by arbitral courts, or 'those very general criteria which could be inferred from the nature and character of the [international] legal order'. States and courts tended to agree that the main purpose of treaty interpretation was to identify and spell out the intention of the draftsmen. However, views differed when it came to specifying how this intention could be found.

The adverse consequences of the lack of legally binding rules in such a delicate area are self- evident.

This tricky area received a balanced and satisfactory regulation in Articles 31-3 of the Vienna Convention.

Basically the Convention gave pride of place to literal, systematic, and teleological interpretation (Article 31.1: 'A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose'). Thus, great weight was attributed to the purpose pursued by contracting parties, as laid down in the text, of the treaty. Also, pride of place was implicitly given to the: principle of 'effectiveness' (ut res magis valeat quam pereat).

Termination

In the past, major Powers made treaties to their advantage and released themselves from treaty obligations when they deemed it fit. The most widely accepted mode of terminating treaties was denunciation by one of the contracting parties.

One of the major advances made in this area in the Vienna Convention was clarification of the concept of ‘material breach’, which one of the parties could invoke as a ground for terminating the treaty or suspending its operation. Thus, under Article 60.3 such a breach consists in ‘(a) a repudiation of the treaty not sanctioned by the present Convention; or (b) the violation of a provision essential to the accomplishment of the object or purpose of the treaty’.

Provisions were also laid down to clarify the role and legal effects of withdrawal from a multilateral treaty; or termination of a bilateral treaty, upon denunciation, when the treaty does not contain any clause regarding its termination or denunciation. Article 56 provided that the treaty is not subject to termination or withdrawal unless: (a) it may be established that the parties had the intention of allowing for this possibility, or ( b)’a right of denunciation or withdrawal may be implied by the nature of the treaty’.

The Convention also spelled out a cardinal principle, namely that, except for what is stipulated by Article 64, the various causes of termination do not make treaties come to an end automatically but can only be invoked by one of the parties as a ground for discounting the treaty. It was also provided hat, in addition to authorizing a party to claim that a treaty should cease, the above clauses could also have a more limited effect: that is to say, they could authorize a party to claim the mere suspension of the treaty.