Clausula Rebus Sic Stantibus

Clausula rebus sic stantibus is the civil-law doctrine that a contract binds only while the circumstances at formation endure, allowing relief when a fundamental change makes performance unjust. Civil-law systems and the Vienna Convention on the Law of Treaties (Article 62, for treaties) recognize it. English law has no general doctrine of changed circumstances; the nearest equivalent is frustration, which discharges a charter only when a supervening event makes performance radically different or impossible, not merely more onerous. A rise in voyage cost, a canal closure that lengthens the route, or war-risk diversion rarely frustrates a charter; the bargain stands unless performance becomes legally or physically impossible.