This book provides a sophisticated analysis of cross-border challenges and problems in the southern African region. It advances explanations that transcend the state-centric narrative that has nationalised cross-border security. It provides insights from non-state actors such as informal cross-border traders (ICBTs), informal cross-border transporters, undocumented migrants, and cross-border communities. It argues that security needs to be understood beyond a state-centric paradigm by focusing on the political, economic, environmental, and societal threats at macro, meso, and micro levels. The book suggests that at the core of cross-border security challenges in the Southern African region is a post-colonial governmentality. This drives the nationalisation of cross-border security as though it is the only security leading to nation-states, in turn depoliticising and invisibilising the security and livelihoods of ordinary people, even when nation-states claim to be protecting the same. The book will be a useful resource for students, scholars, and researchers of African Studies, Border Studies, Human Geography, Migration Studies, Development Studies, International Studies, International Relations, Political Science, and Security Studies.