Qualifying research work as manuscript. Doctoral thesis for an academic degree of the Doctor of Philosophy in specialty specialty 293 – International law.– National University «Odessa Law Academy», Ministry of Education and Science of Ukraine, Odessa, 2021.
The dissertation is the first in Ukrainian science of international law special complex research of the principle ofestoppel as the general principle of international law. The paper presents a number of author’s concepts, ideas and conclusions, which are characterized by scientific novelty.
The dissertation reveals the peculiarities of the development of the estoppel principle at different stages of the formation of international law, establishes the connection between the estoppel principle and its legal basis – the principle of good faith, distinguishes the estoppel principle with the institution of unilateral acts of the state, on the basis of which the independent nature of the estoppel principle is substantiated which by its essence and the direction of the regulatory influence is a completely independent principle of law, and as one of the general principles of law (according to Article 38 of the Charter of the International Court of Justice) is included into the system of sources of international law.
Estoppel is revealed as a common law principle, which coexists with the principles of good faith, adversarial proceedings, proper performance of obligations and in a certain sense is a continuation of them.
The tasks and functions of estoppel in the regulation of international relations are characterized. Its task is to prevent the unjust deviation of one state from a previously taken position on a certain issue of fact or law adopted by another state as a basis for its actions or refrain from them, which, if not followed, will act to the detriment of another state. It has been proved that, performing its inherent stabilizing role in modern international law, estoppel ensures the legal security of subjects of international law through the prescription of the sequence of states’conduct. The functional orientation of the estoppel principle in this direction is driven by its dual meaning –as quality of procedural and substantive law. In procedural law, estoppel should be understood as a rule or principle according to which the party to the dispute has no right to change its legal position to the opposite, if such unfair contradictory conduct harms the other party, and violates fundamental principles of procedural law, including good faith and competitiveness. In substantive law, estoppel is a legal mechanism that regulates the possibility of appealing against the nullity of an obligation on the basis of dishonest conduct of a party. In other words, estoppel in the substantive sense is a kind of prevention, which prohibits the parties to refer to the non-compliance or invalidity of the obligation after fulfilling its conditions, if their conduct has already confirmed the will to fulfill it.
