Fourth-Generation Warfare (4GW) represents not only a tactical or doctrinal mutation but a civilisational turning point in the genealogy of organised violence. Emerging from the fractures of decolonisation and the ideological exhaustion of the Cold War, 4GW redefined victory from territorial domination to narrative legitimacy, transforming war from a state-centred enterprise into a contest over meaning itself. It marks the era when perception, not position, became decisive, and when moral narratives could invert asymmetries of power. Drawing on Realism’s emphasis on survival, Idealism’s concern with legitimacy, Constructivism’s focus on identity and social meaning, and the anticipatory logic of AI and Cognitive Systems Theory (AICST), this chapter situates 4GW as the hinge between industrial and cognitive epochs of war. Through comparative case studies—Vietnam’s media insurgency, the Soviet–Afghan conflict’s ideological proxy logic, and Hezbollah’s hybrid warfare—the analysis demonstrates how legitimacy, temporality, and information became strategic resources in themselves. Methodologically, it combines historical-comparative synthesis with discourse analysis to trace how insurgents weaponised social belief systems and communicative technologies to offset material inferiority. The chapter concludes that 4GW exposes the paradox of modern warfare: its capacity to democratise resistance while simultaneously diffusing violence into the moral, digital, and everyday realms of political life.