The West’s treatment of irregular fighters in the “war on terror” was highly problematic. This article contends that we must look beyond the assumption that political and strategic considerations compromised the law and led to the “invention” of the category of the “unlawful combatant.” Rather, the law of armed conflict itself includes strong exclusionary mechanisms towards irregular fighters. These exclusionary strands in the law came to dominate the West’s strategic decision-making on the treatment of irregular fighters. Moreover, the fact that irregular fighters became such a vital issue post-9/11 was not a result of the war on terror being a new kind of war, as has often been argued. Rather, this article suggests that it reflects an identity crisis of the West’s regular armed forces at the start of the twenty-first century.