A principle used in international law to justify a state from ousting itself from the binding nature of a treaty that it has previously signed and adopted, citing changed circumstances.
In Trans World Airlines, Madam Justice Sandra Day O'Connor of the Supreme Court of United States wrote:
"A treaty is in the nature of a contract between nations. The doctrine of rebus sic stantibus does recognize that a nation that is party to a treaty might conceivably invoke changed circumstances as an excuse for terminating its obligations under the treaty."
No state is bound to a treaty which is has not accepted and so, as Lawrence Farley writes:
"... even then, a state exercising the principle of rebus sic stantiubus (changed circumstances), may later renege on an agreement."
Such an argument would have no weight in contract law (as specifically enshrined in the Latin maxim pacta sunt servanda and except, perhaps, to the extent that equity might apply) but in international relations, it is thought best to accommodate rebus sic stantibus.
However, it has not been received and applied without controversy as to allow it to be wielded without control jeopardizes the very existence of international law and order, and certainly the word of virtually every treaty.
The entire Latin phrase is conventio omnis intelligitur rebus sic stantibus, shortened to rebus sic stantibus.
In his 1929 treatise on international law, Henry Wheaton noted that there were several ways in which a state claim to be free of treaty obligations. Many treaties contain opt-out mechanisms. But as to rebus sic stantibus, treaties:
"... are liable to dissolution on demand of one of the parties on a vital change of circumstances, on the principle conventio omnis intelligitur rebus sic stantibus.
"It is clear that (rebus sic stantibus) is a very dangerous factor and that it cannot be misused but, on the other hand, the principle that no treaty can be broken is equally dangerous. It is fair to say that each state contracts in the belief that it is not endangering its national life and development, and if a treaty in fact proves to threaten these essentials, it can insist on revision or cancellation. Yet there must be grave cause; mere loss or inconvenience is not enough...."
- Farley, L., Plebiscites and Sovereignty (London: Mansell Publishing Limited, 1986), page 8
- Keith, A., Wheaton's Elements of International Law, Volume 1 (London:: Stevens & Sons, Limited, 1929).
- Trans World Airlines, Inc. v. Franklin Mint Corp., 466 US 243 (1984)