Disputes — Unilateral means of redress short of war — Retorsion — Iranian Assets Regulations issued by United States following seizure of United States hostages in Iran — Whether an independent cause of ensuing events — Effects on lease agreement — Iran- United States Claims Settlement Declaration, 1981 — The law and practice of the Iran- United States Claims Tribunal

State responsibility — Nature and kinds of — For debts — Payments under lease agreement — Lessee wholly owned and controlled by Government of Iran — Iranian Assets Regulations issued by United States following seizure of United States hostages in Iran — Whether frustrating purpose of lease — Whether making performance impossible — Applicable law — Whether lease discharged — Foreseeability of frustration — Attributability of supervening events — Whether United States acts an independent cause of ensuing events — Consequences of discharge of lease — Arbitration costs — Iran-United States Claims Settlement Declaration, 1981 — The law and practice of the Iran-United States Claims Tribunal