情势变更原则,就是传统民法理论上所称的可免责原则,它包含了不可抗力部分,但免责范围又比不可抗力更为广泛,更为灵活。从直观意义上说就是由于不可抗力或一方当事人虽无过失但又无法防止的外因,致使双方签订的合同无法履行或不能完全履行,若继续履行将显失公平时可允许变更或解除原 The principle of changing circumstances is the principle of exemption claimed in the theory of traditional civil law. It contains parts of force majeure but its scope of exemption is broader and more flexible than force majeure. Intuitively speaking, this is due to force majeure or the external factors that can not be prevented by one of the parties, which are not faultless. As a result, the contract signed by both parties can not be performed or can not be fully performed. If the performance of the contract can be obviously unfair, the original contract may be changed or released