This episode explores the conceptual structures that undergird irregular warfare. Dr. Thomas Marks and Chief Warrant Officer Maurice "Duc" DuClos join our hosts, beginning the discussion by addressing the various ways the US government defines irregular warfare. They continue by examining the interplay between nations and nonstate actors—and how sovereign states are increasingly adopting methods traditionally employed by irregular actors to achieve their larger geopolitical aims. Finally, they reflect on different frameworks that strategic- and operational-level professionals can use to plan, implement, and evaluate irregular warfare campaigns more effectively.