This article is devoted to analysis of political and legal problems arising in the development of science and technology at the international and national levels in connection with geo-economic and geopolitical sanctions. The purpose of the work is to substantiate the approach to scientific and technological sanctions as barriers in international cooperation in the area of theoretical science and technology, which are of a political and legal nature. In the course of the analysis it was possible to prove the validity of singling out the category of scientific sanctions, which are selective, in contrast to political and economic sanctions that negatively affect the scientific and technological complex of specific states, but do not have a selective nature. The barriers that arise in the course of international scientific and scientific-technological cooperation are systematized. The nature of scientific sanctions has been established as barriers that have a strong-willed basis and are aimed at curtailing cooperation within the framework of certain organizational and legal forms. It has been established that the legal version of scientific sanctions is the unilateral termination of international contractual relations, as well as the adoption of decisions on the termination of ties by scientific and scientific-educational institutions that have the right to make autonomous decisions. The conclusions of this article are as follows: as a method to respond to sanction challenges in the field of STI, the formation and implementation of a special state policy aimed at providing legal support for special support for the R&D sector is occurring, as well as preserving the remaining scientific cases while developing and deepening alternative areas of international cooperation. This category of measures should not be perceived as a series of countermeasures that would lead to a further curtailment of ISTC, but as measures that should ensure its development, including in other geographical areas and based on the increased use of scientific diplomacy methods.