This book provides a comprehensive analysis of the concept of state responsibility under international law, exploring its evolving dimensions in contemporary global governance. It examines the principles governing state responsibility, emphasizing the role of customary international law and its application in various contexts. The book delves into key areas, including transnational pollution, human rights violations, cyberattacks, nuclear activities, and state obligations in maritime domains. It also discusses the legal implications of state actions in cases of infectious disease outbreaks and liability concerning international organizations and corporations. A significant portion is dedicated to the International Law Commission’s Draft Articles on State Responsibility, tracing their development and relevance in modern international disputes. Through detailed case studies and judicial precedents, the book critically evaluates the challenges in attributing state responsibility and the mechanisms for reparation. It serves as a crucial resource for scholars, policymakers, and legal practitioners in understanding the complexities of state accountability in international law.