The article reveals the international framework of political and legal liability of states for committing acts of genocide, ecocide, and using weapons of mass destruction. It is emphasized that these areas form a separate legal responsibility institution within international law. The author emphasizes the lack of unity between theoretical and practical aspects of legal regulation of using weapons of mass destruction, as well as the role that liability plays in the progressive development of law. The paper also highlights topical issues related to the paradigm shifts in modern international law due to the cases of genocide, ecocide, and WMD. The study aims to analyze international legal norms and practices of holding states accountable for the crimes of genocide, ecocide, and use of weapons of mass destruction. The following methods were employed in the course of this research: systemic, comparative legal, historical and legal, structural and functional, and generalization. The article emphasizes that most international crimes are committed with the support or under the control of collective entities, especially states. Nevertheless, international law has tended to impose responsibility for such crimes not only on certain people but also on states. The predominant response of the international community to international crimes was to impose responsibility on specific persons to the extent that it has been directed through international responsibility law. In this regard, it has been symbolized by prosecuting particular criminals through international criminal courts and tribunals.