he resurgence of the March 23 Movement (M23) in 2025 has reignited one of the most protracted security crises in the Great Lakes region of Africa, raising urgent questions about the relationship between state sovereignty and the evolving norms of international law. Despite its earlier defeat in 2013, M23 has re-emerged as a formidable non-state actor, reportedly supported by regional powers such as Rwanda and Uganda. These developments have intensified debates around the legitimacy of cross-border military interventions, the erosion of Westphalian sovereignty, and the legal thresholds for humanitarian and security-driven involvement in domestic conflicts. Against this backdrop, the article employs a qualitative research design, utilizing comparative case studies, legal document analysis, and discourse review. It draws on theoretical frameworks including Regional Security Complex Theory (RSCT), Responsibility to Protect (R2P), and hybrid sovereignty to examine how African states and international actors negotiate the tension between sovereignty and interventionism. Key questions addressed include: under what legal frameworks are military interventions in Africa justified; how regional organizations such as the African Union (AU), East African Community (EAC), and the United Nations (UN) mediate such crises; and what implications the M23 crisis holds for the future of sovereignty and security governance in Africa. Findings reveal systemic gaps in enforcement mechanisms, the inadequacy of multilateral responses, and the increasingly contested nature of sovereignty in conflict zones. Regional and international interventions are frequently hindered by competing political agendas, poor coordination among security actors, and the politicization of humanitarian norms such as R2P. The article concludes that the M23 crisis underscores the urgent need to strengthen regional security cooperation, reinforce international legal norms, and address the structural drivers of insurgencies in the Democratic Republic of Congo and beyond. Coherent, coordinated, and accountable multilateral mechanisms are essential to safeguard both state stability and the protection of civilians.