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).