This comparative study critically examines the implementation trajectories of South Sudan's two principal peace accords: the 2005 Comprehensive Peace Agreement (CPA) and the 2018 Revitalised Agreement on the Resolution of the Conflict in South Sudan (R-ARCSS). It argues that structural flaws in power-sharing arrangements, coupled with the absence of robust enforcement mechanisms and the persistent political economy of conflict, have systematically undermined durable peace. The analysis employs a structured, focused comparison to evaluate key provisions on security sector reform, transitional governance, and wealth-sharing. The findings reveal that while the R-ARCSS learned from certain CPA shortcomings, it replicated critical vulnerabilities, leading to a cyclical pattern of fragile peace and renewed instability. The study concludes that sustainable peace requires moving beyond elite-centric pacts to address foundational issues of state legitimacy and inclusive political community.