Article 79 of the CISG provides that “[a] party is not liable for a failure to perform any of his obligations” if the party has encountered a certain impediment defined therein. It was once depicted as “the Convention’s least successful part of the half-century of work.” It has been thirty years since the CISG took effect. However, the interpretation of Article 79 is as old and unsuccessful as ever. For one thing, it has long been interpreted against our intuition, not to exempt a party from specific performance claims. For another, the controversy has long continued unsettled over whether a party could be exempted in the so-called “hardship” cases. Lastly, where an event fundamentally alters the equilibrium of the contract because of the increased cost of performance, judges’ power to adapt the contract is urgently desired, but no reasonable basis in provisions of the CISG has been suggested.

This article demonstrates that (1) Article 79 as a rule exempts a party from specific performance claims, (2) the so-called “hardship” cases are within the ambit of Article 79, and that (3) judges can adapt contracts through what this author terms a “reasonable expectation test.”