ABSTRACT
The Horn of Africa presents a rich opportunity to explore the complexity and nuances that underpin regionalism broadly, and particularly how interregionalism is shaped by divergent interests and contestations. Based on analyses of primary and secondary sources as well as participatory observations conducted in the region, this chapter contributes to the scholarly literature on interregionalism in several ways. It begins by describing how the conceptual aspects of interregionalism have evolved as useful social scientific tools. Through an agential constructivist lens, this chapter then identifies and examines the unintended consequences of bifurcated interregionalism between the regional organisation Intergovernmental Authority on Development and informal regionalism in the Horn of Africa. It analyses the overlap between these two regionalisms and examines the attendant unintended consequences in socio-economic, trade and security dimensions. The study concludes by examining the implications of how the unintended consequences of interregionalism in East Africa impact regional governance challenges.
