The research argues the incompatibility of the principle of distinction as codified/internationally interpreted in modern insurgency warfare. It argues that current IHL is narrow in scope to regulate modern insurgency warfare, establishes unattainable thresholds for its application, therefore becoming inapplicable and creating gaps in law. This unsuitability in application results in lengthy insurgency wars, and directly increases civilian casualties in these combat environments. This research concludes with recommendations for the amendment and/or development of new guidelines in order to regulate this common type of warfare and reduce its deadly impact on the civilian population.