New Theories of the Partisan? A Comparative Inquiry into the Legal Classification and Treatment of Detained Unlawful Combatants

This essay analyses the legal status of combatants serving in military formations deemed unlawful, adopting a comparative approach that moves across historical periods and contemporary jurisdictions. It begins by outlining the earliest regulatory schemes and the associated opinio iuris, tracing a line of development that leads to present‑day practice. By considering how the United States, Israel, and the Russian Federation classify and treat prisoners of war captured from formations labelled as unlawful or terrorist, the study shows how current conflicts have pressured—and in some cases altered—the normative contours of ius in bello. Within the historical dimension, the inquiry also highlights the enduring interplay between ius in bello and ius ad bellum, an interaction that has significantly shaped the modern architecture of the law of armed conflict.