The Vienna Convention provides a clear conceptual framework for treaty interpretation. It also provides an outline to examine the way in which UK courts have addressed the principles expressed in it. It is the whole of the interpretive code in the Vienna Convention that should be applied and not just the general principle referred to in Commerzbank. The general principles are set out in art. 31 as follows:
‘(1)A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to terms of the treaty in their context and in the light of its object and purpose.