Theories in international relations, predicated on particular assumptions, for explaining the relationship between regional economic integration and regional security miss the challenges to security in the developing world. Unlike the developed world, regional interdependence in much of the developing world engenders negative externalities. The relationship between regional economic integration and regional security depends on the nature of the security threats that define the region – traditional state vs state threats on one hand versus new security threats on the other hand. The nature of the security threat, or security dilemma, will determine how different forms of regional economic integration, laissez faire, functional, and developmental, define or re-define a particular regional security order. Building a ‘security community’ in the developing world, therefore, calls for new architectural principles. In the case of southern Africa, both, laissez faire (free trade area) and functional cooperation (spatial development initiatives) will foster insecurity rather than security.