The purpose of this thesis is to explore the applicability of the principle of discrimination in Afghanistan. Two research questions seeks to find out whether it is possible to draw a distinction between combatants and non-combatants in Afghanistan, and whether it is possible to prepare soldier for difficult situations arising when making this distinction. Just war theory is used as a basis for the analytical framework. The study concludes that the traditional group-based criteria for distinguishing between combatants and non-combatants in conflicts are not applicable in Afghanistan. Based on Larrys May’s interpretation of just war theory I suggest that a distinction in insurgency conflicts should rather be based on a behaviour-based approach, as this approach proves more successful in Afghanistan today.