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

when the parties enter into a contract, they are obliged to implement its obligations, but sometimes events occur that make it impossible to execute the contract or runtime status than the time of conclusion of the contract is fundamentally different. these events are referred to as legal excuses if eligible, the parties are exempt from the obligations and responsibilities. the most important legal excuses, the common law doctrine of frustration and force majeure is that exemption from contractual obligations and responsibilities of the parties. there are many similarities between the frustration of contract at common law and the rights of force majeure including iran's rights and the principles of international commercial contract law principles briefly called unidroit. frustration of contract occurs when suddenly accident and without negligence of the parties, contract enforcement is impossible or the purpose of the contract disappears as a result frustrate the contract. the closest institution to force majeure theory is the doctrine of frustration of contract. force majeure occurs when the execution of the contract without negligence of the parties, in an outside accident, non-shedding and unpredictable is impossible.