Evaluating the Effectiveness of the Committee Against Torture (CAT) in Achieving State Compliance: A Case Study of New Zealand, Zambia and Mexico

Background: This study examines the effectiveness of the Committee against Torture (CAT) in achieving state compliance with the United Nations Convention against Torture (UNCAT). Although the prohibition of torture constitutes a jus cogens norm in international law, torture persists globally, revealing a serious gap between states’ formal ratification of UNCAT and the practical realisation of its obligations. While the CAT provides a comprehensive monitoring framework–through periodic reporting, individual complaints, and general comments–it lacks binding enforcement powers, raising questions about its practical impact in diverse legal and political settings. Methods: Using a qualitative, comparative legal approach, this study evaluates the extent of CAT’s influence on domestic compliance in three states–New Zealand, Mexico, and Zambia–selected for their legal system diversity, geographical distribution, and distinct compliance trajectories. The analysis draws on CAT concluding observations, state reports, national legislation, civil society shadow reports, and third-party documentation. Each country is assessed for both formal compliance (ratification, legislative incorporation, reporting) and substantive compliance (investigations, accountability, and redress mechanisms). A structured comparison model ensures consistency across cases. Results and Conclusions: Findings reveal stark contrasts. New Zealand demonstrates strong formal compliance, with detailed legislation and constructive CAT engagement. However, gaps remain concerning Indigenous rights, detention safeguards, and procedural protections. Mexico, despite enacting the 2017 General Law on Torture, continues to face systemic issues, including widespread torture, impunity, and militarised security forces. Zambia, the weakest performer, lacks specific anti-torture legislation and institutional frameworks, resulting in minimal implementation. Across all cases, CAT’s impact depends heavily on domestic political will, institutional independence, and the participation of civil society. The study concludes that while CAT serves a critical normative and advisory role, its influence remains constrained in practice by its non-binding nature. Strengthening CAT’s follow-up mechanisms, enhancing regional cooperation, and integrating recommendations into national legal and political agendas are essential for bridging the gap between formal ratification and the actual prevention of torture.