Hardship as an adaptation reason

By entering into a synallagmatic contractual transactions, the parties agree to each other's performance: Each party, as the debtor, commits itself to the other party as the creditor to provide a specific performans. When concluding a contract, each party usually has certain ideas as to how it will perform the service it owes and which issue, which fulfillment efforts are necessary. These ideas of the parties may prove to be incorrect for a variety of reasons. Often the debtor has not given enough thought or misconception about the necessary fulfillment efforts or has miscalculated or misjudged their determination. At times, the debtor was not aware of certain circumstances already at the time the contract was concluded. And sometimes it happens that after the conclusion of a contract, events or circumstances occur which increase the compliance effort and thus make the provision of the service more difficult. This last case, the termination of change of circumstances after the conclusion of the contract (Turkish Code of Obligations Art. 138), forms the subject of the present work. The debtor remains obliged to provide benefits in the event of subsequent performance difficulties. He has to overcome the difficulties encountered, even if it requires greater fulfillment efforts than he had thought when the contract was concluded. Pacta sunt servanda. If, however, the effort required for the fulfillment is much greater than anticipated, the debtor's commitment to the contract may be felt to be hard and unreasonable. The basic principles of theory of hardship is that if performance of a contract is possible, but a fundamental changes of circumstances surruonding the contract had rendered performance, so that continued performance by the party affected to undue hardship. So, the affected party can invoke the principle of clausula rebus sic stantibus. This means the certain fundamental changes of circumstances must remain unchanged.