The phenomenon of irregular forces (guerrillas, partisans, terrorists) has occurred frequently throughout history, with the terminology changing depending on the perspective. However, certain parallels in structure, emergence, and tactics can still be observed today. In the current discussion surrounding "the fight against transnational terrorism" and "asymmetric warfare," the focus is on understanding these phenomena and developing holistic, goal-oriented, and effective action patterns. Dirk Freudenberg provides an overview of the application-oriented theoretical approaches of specific thinkers. He examines the impacts and influences on regular armed structures as well as their interactions and responses to irregular forces. Additionally, he presents a historical case study.