The book investigates the emergence and the development of irregular fighters, such as guerrillas, rebels, insurgents, and terrorists throughout the history of modern war. It presents a historically-based critique of the twenty-first century notion of the irregular fighter as an 'unlawful combatant'.

The making of the irregular fighter, 1740-1815 -- The nineteenth century: rebels, rifles, and the laws of war -- The Second World War: anti-partisan warfare, genocide, and the rebirth of the auxiliary fighter -- Wars in the colonies: orientalism and the social production of colonial subjects -- Irregular fighters in the twenty-first century: between "unlawful combatants" and "rebel" auxiliaries -- Conclusion.