Regional organisations in Africa are often tasked with both conflict management and economic integration, yet these objectives can pull in different directions. In the Horn of Africa, IGAD operates within a context where persistent security crises crowd out deeper integration efforts. This study examines how this structural tension shapes the political economy of regionalism, with comparative reference to the EAC, SADC, and ECOWAS. Drawing on regional integration theory, the security–development nexus, and African regionalism, the study combines institutional analysis of IGAD’s legal frameworks and budgets with comparative analysis across regional organisations, trade-flow interpretation, and interviews with regional stakeholders. The findings show that the tension between security and integration is not a temporary constraint but a durable feature of regional governance, reproduced through institutional and political mechanisms that reshape incentives, authority, and resource allocation over time (Haas 1958; Balassa 1961; Söderbaum 2004; Taylor 2003). In IGAD, security imperatives often dominate organisational priorities, limiting progress on trade integration and economic coordination. Variation across regional bodies reflects differences in mandate balance, member-state interests, and levels of economic interdependence. The contribution lies in demonstrating how security pressures structurally condition regional integration outcomes, challenging linear models of economic integration and highlighting the need to align security and economic mandates. It argues that more effective regionalism requires institutional redesign, political bargaining, and accountability mechanisms that address the underlying distribution of power among member states (Bach 2016; Acharya 2009;