This article develops misaligned mediation leverage as an analytical lens for understanding mediation failure in protracted conflicts: leverage, consent, and the political economy of negotiation spoilers. It argues that mediation fails when leverage is directed at formal principals while the real capacity to violate agreements is dispersed across semi-autonomous commanders who face different incentives than negotiators at the table. Drawing on process tracing of the igad-led mediation processes (2014–2018); comparative analysis with angola's lusaka protocol (1994) and liberia's accra agreement (2003); mediation team interviews; application of formal game-theoretic models of bargaining under incomplete information., the paper links the theoretical debates identified in negotiation theory (zartman's 'ripeness'; touval & zartman on mediation); spoiler theory (stedman); principal-agent problems in international mediation. develops a model of how mediator leverage interacts with the internal principal-agent dynamics of armed factions to explain why mediated agreements collapse. to a comparative and historically grounded reading of South Sudan and the related cases assembled in the research design. The article advances three core claims. First, the 2015 ARCSS collapsed not because mediation was absent, but because leverage and consent were concentrated at the leadership tier while field commanders retained incentives and capacity to defect. Second, spoiler behaviour is best explained by principal-agent divergence within armed movements rather than by a simple binary between peace-seekers and rejectionists. Third, sanctions and coercive diplomacy are effective only when paired with enforcement architectures that can alter the calculations of commanders, financiers, and neighbo