pondering about doctrine of frustration of contract on the common law and comparison with the force majeure on the principles of international commercial contract and iran law

when the parties to conclude a contract, bounding to performance their contractual obligations, but sometimes occur events that to make performance of obligations under a contract impossible or the circumstances of the time of performance of the contract substantially differentiate with the time of the time of the conclusion of the contract . these events are referred to as legal excuses, if they qualify, will be exempt from its obligations and responsibilities of the parties. the most important legal excuse, is the doctrine of frustration on the common law and force majeure, which leads to an exemption from contractual obligations and responsibilities of the partiess. due to a lot of similarities between the doctrine of frustration on the common law and the force majeure institution in the iran law and principles of international commercial contracts, which are briefly called unidroit. in this article attempts to explain the doctrine of frustration of the contract has been fully evaluated and then explain the force majeure and we compare it with the frustration of contract.