In this archive piece from 2003, Ann Mason examines the limits of international relations theory in addressing conflicts in the global South, which had risen to the top of research and policy agendas in the aftermath of 9/11. She uses the case of armed conflict in Colombia to interrogate how international relations theory might better engage three issues relevant to the developing world: the connection between state weakness and violence, how security threats within a country are related to dynamics beyond a country’s borders, and the North-South power disparity.