State responsibility — Nature and kinds of — For revocation of, or interference with, concessions or concessionary contracts — Purported nullification of contract by Iran — Whether engaging State responsbility — lran — United States Claims Settlement Declaration, 1981 — The law and practice of the Iran-United States Claims Tribunal

Disputes — Arbitration — Procedure — Competence — Contractual claim — Purported annulment of contract — Whether affecting jurisdiction — Iran-United States Claims Settlement Declaration, 1981, Article II(1) — The law and practice of the Iran-United States Claims Tribunal