<![CDATA[Background: Political crises often expose structural weaknesses in State governance, raising critical questions about the extent of State responsibility under international investment treaty law, particularly in ensuring Full Protection and Security (FPS) for foreign investors. The De Sutter v. Madagascar (II) case provides a relevant context to reassess how domestic political instability interacts with legal obligations of Host State. Methodology: This study employs a doctrinal legal research method using a case study approach centred on the De Sutter v. Madagascar (II) award and a conceptual approach based on the doctrines of due diligence, FPS, and State responsibility. Objectives: The paper aims to explain how State responsibility operates during political crises and to develop practical pathways for future prevention of investment treaty violations through strengthened legal and institutional frameworks. Findings: The analysis shows that political instability does not reduce international obligations but increases the expectation of vigilance, preparedness, and coordinated State action. Liability arises primarily from the failure to anticipate and respond to foreseeable risks. At the same time, the study identifies preventive measures, including early warning mechanisms, institutional coordination, and post-crisis judicial integrity, as essential tools to minimise future violations. Originality/Novelty: This research proposes a clear preventive action of State responsibility by integrating a context-sensitive due diligence standard with concrete institutional reforms, offering a focused framework for managing recurring political instability.]]>
