This article develops institutional ambition without autonomy as an analytical lens for understanding the african union's peace and security architecture: between institutional ambition and political impotence. It argues that the African Unions peace and security architecture embeds ambitious norms but lacks the delegated fiscal authority, operational independence, and member-state discipline needed to transform those norms into consistent coercive or preventive action. Drawing on comparative case analysis of amis (darfur), amisom (somalia), misca (car), and mnjtf (lake chad basin); budget analysis of peace fund contributions; discourse analysis of psc communiqués; interviews with au commission peace and security department officials., the paper links the theoretical debates identified in regime theory (keohane; young); principal-agent analysis of international organisations; african regionalism theory (acharya; bach; murithi). examines why the au's formally ambitious peace and security institutions — psc, apsa, acirc — consistently underperform relative to their mandate. 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, AU underperformance is generated by the interaction of weak financing, cautious member states, and fragmented command arrangements rather than by institutional absence alone. Second, donor dependence has enabled operations but has also constrained agenda setting, force generation, and the strategic autonomy associated with the slogan African solutions to African problems. Third, the AU performs best when regional and international partners align around a limited mandate, but it struggles when political incumbents treat peace architectur