Legal Impossibility in Practice Due to the Obligation to Implement Annulment Decisions and the Principle of Legal Security

One of the most important requirements of the rule of law is the obligation to implement judicial decisions. Both the Constitution and the Administrative Procedure Law No. 2577 have pointed out this obligation. Annulment decisions made as a result of an application to the administrative court are peculiar in this context. In some cases, it is not possible to apply these decisions in full retrospectively, and this situation is explained with the concepts of de facto and legal impossibility. Another situation that causes legal impossibility is the possibility that the full retroactive application of annulment decisions will harm the principle of legal security. One of the main arguments put forward in this regard is the existence of other transactions related to the canceled transaction and the existence of some gains based on the canceled transaction. In the case of Turkey, legal regulations are made by the legislator or the administrations, or without such a regulation, the decision is not implemented on the grounds of legal impossibility. In this study, taking the decisions of the Council of State as the axis, it has been examined whether there is a legal impossibility in the implementation of the decision and the judicial and administrative mechanisms that will prevent such a result from occurring.