Rereading precedence and delay of obligation and termination of the contract in Iranian law, with emphasizing the background of issue in the laws on Sample countries

One of the important issues of contract law in Iranian law, Germanic Roman law, Common law rights, is guarantee of the obligation to fulfill the obligation, and how it relates to contract termination. The question is this regard is that in the studied systems what is the procedure for the termination of the contract and the obligation to fulfill the obligation? In this article to study the priority and delay of fulfilling the obligation and termination of the contract with analytical descriptive method and we make inference in Iranian law, Germanic Roman law and Common law; and we will provide the answer to the research question. The research hypothesis in answering this question is that legal systems have presented different ideas. Some legal systems consider the priority of the execution of the same obligation. According to these legal systems, termination is secondary on requiring the defendant to fulfill contractual obligations; therefore, the petitioner must first request a lawsuit for the obligation to fulfill obligation; but some others in terms of customary consideration, have priority to the contract. The innovation of the research is that the issue has not been dealt with in a comparative way.