Contemporary democratic systems increasingly rely on preventive and risk-based forms of governance designed to anticipate and neutralize potential threats before harm occurs. Preventive detention, surveillance regimes, administrative restrictions, electronic monitoring, and other anticipatory measures have expanded beyond exceptional contexts and now function as ordinary mechanisms of state regulation. This development reflects a broader transformation within criminal justice systems, shifting from retrospective punishment based on proven conduct toward preventive intervention grounded in perceived dangerousness, risk assessment, and security rationality. Against this background, the paper examines the growing tension between preventive governance and the right to liberty protected under Article 5 of the European Convention on Human Rights (ECHR). The study adopts a doctrinal and analytical legal approach based on the examination of Article 5 ECHR, relevant ECtHR jurisprudence, and contemporary scholarship on preventive justice, risk governance, and constitutional limitations on state power. It combines doctrinal legal analysis with conceptual constitutional critique to evaluate the implications of normalized preventive intervention within democratic systems. The article argues that preventive governance increasingly transforms liberty from a safeguard against arbitrary state power into a conditional status dependent on assessments of future risk and security considerations. Through an analysis of Article 5 ECHR, ECtHR jurisprudence, and broader preventive governance practices, the paper critically examines how anticipatory state intervention challenges principles such as legality, proportionality, foreseeability, and individual culpability. Ultimately, the article questions whether Article 5 ECHR can continue to function effectively as a safeguard against arbitrariness within systems increasingly governed through preventive state rationality.