Defenses of Impossibility of Performance and Frustration of Purpose

Parties in complex commercial cases that are accused of defaulting on or breaching a contract may invoke the defense of impossibility, arguing that performance of contractual obligations was rendered impossible by an intervening event. Under New York law, those arguments rarely make it past the motion stage. Courts apply the doctrine narrowly, only to executory contracts and only where the intervening event was both unforeseeable and destroyed either the contract's subject matter or the means of performance. The related doctrine of frustration of purpose may apply more broadly, but only where it would make little sense to perform on a contract because of an intervening event. The narrowness of these doctrines — and their questionable utility for litigators — underscores the importance of striving during the contract drafting process to include contingency clauses providing for foreseeable possibilities and language making clear the contract's purpose.