Structural causes of military co-location and the (in)feasibility of precautions in defence

The “feasibility” of passive precautions in international humanitarian law (IHL) is typically applied as an operational, moment‑of‑attack assessment. This article instead argues that feasibility should be conceived as a legal-spatial construct which takes into account that prior decisions or omissions in spatial planning, infrastructure design, governance and political economy often limit States’ decision space at the moment of conflict. In the article, we develop a four‑driver framework to explain the structural causes of military–civilian co‑location in urban settings, and demonstrate how reconceptualizing feasibility as the end product of antebellum measures can expand States’ available action space to enhance civilian protection.