This article develops selective engagement after unipolarity as an analytical lens for understanding u.s. foreign policy toward sub-saharan africa in the post-unipolar moment: strategic competition, selective engagement, and the limits of liberal internationalism. It argues that post-unipolar U.S.-Africa policy is best understood as a shifting compromise among liberal internationalist rhetoric, strategic competition, counterterror imperatives, and bureaucratic fragmentation across security, development, and commercial agencies. Drawing on comparative policy analysis across bush, obama, trump, and biden africa strategies; content analysis of nss documents, congressional hearings, and africom budget data; structured elite interviews with former state department and nsc africa directorate officials., the paper links the theoretical debates identified in hegemonic stability theory and its critics; liberal internationalism (ikenberry) versus offshore balancing (mearsheimer & walt); african international relations theory (acharya; lumumba-kasongo). situates u.s.–africa policy within structural changes to the international order. 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, successive administrations maintained a discourse of democracy and partnership, yet repeatedly prioritised security access and regime cooperation where strategic interests were judged to be high. Second, Sino-American competition has expanded African bargaining room in some arenas, but it has also intensified transactionalism and reduced the credibility of value-based conditionality. Third, the coexistence of AFRICOM, USAID, MCC, Treasury, and diplomatic priorities creates a persistent