Book excerpt: In this book, Hanna Samir Kassab develops a theoretical framework that explains the formulation of power vacuums and examines their impact on the international system. A power vacuum is the fundamental absence of legitimate state authority over a geographic territory, and it is a space free of governance. With no state authority governing a geographical region, opportunistic states and organized criminal and terrorist networks may attempt to control that space. Using a variety of historical examples and centering his analysis on ungoverned spaces rather than great powers, Kassab uncovers neglected areas of great power competition. Part 1 discusses state actors: specifically, the strategic space of the Arctic, the Middle East and Africa, and Afghanistan and Central Asia. Part 2 examines non-state actors, such as terrorist networks and organized criminal networks, and the formulation of paramilitaries. Power Vacuums and Global Politics is the perfect volume for both undergraduate and graduate courses in international relations, security studies, political science, comparative politics, international political economy, and war and peace.