(20) Court notes that the Treaty contains no provision expressly excluding certain matters from the jurisdiction of the ICJ, [but even if the text could be interpreted], as excluding the jurisdiction of the court to test the lawfulness of such measure, it could also be understood as affording only a defence on the merits. Art XX.1.d does not restrict its jurisdiction in the present case but is confined to affording the parties a possible defence on the merits to be used should the occasion arise
(27) [Regarding art I as basis from jurisdiction] the court considers that such general formulation cannot be interpreted in isolation from the object and purpose of the Treaty in which it is inserted
(31) The objective of peace and friendship proclaimed in art I is such as to throw light on the interpretation of the other treaty provisions and is thus not without legal significance but cannot, taken in isolation, be a basis for the jurisdiction of the court.
[Jurisdiction was found in art X, commerce and ancillary activities, where a dispute existed between the parties]
(51) [Since] Iran oil production was a vital part of its economy, it constituted an important component of its foreign trade