Critics of non-uniformed ‘irregular’ warfare argue that it is unfair both to non-combatants and to enemy ‘regulars’. I dispute this view by outlining the ‘problem of in bello justice’, which concerns how the leaders of a people forced to fight a just war should distribute risks within their own population. In so far as all are the victims of aggression or unjust occupation, I argue, no citizens on the just side are morally liable to attack. But to benefit from the restraining effects of discrimination, some members must be rendered legally liable. Political leaders must therefore find the most appropriate distribution of the risk of harm: first, by deciding which and how many citizens to select as ‘combatants’; and second, by specifying how far to distance combatants from civilians. I identify four normative considerations that must be taken into account: each possible arrangement must (1) fulfil basic requirements of fairness domestically; then, between equally fair arrangements, leaders ought to determine which offers the most auspicious balance between (2) the goal of survival (of the society and as many of its members as possible) and (3) the goal of winning and, hence, eliminating the injustices that caused the war; finally (4) the arrangement should not be unfair to enemy combatants. On this basis, I argue that in spite of the increased risks it poses to civilians, limited ‘irregular’ warfare might be deployed legitimately against occupiers where using uniforms would render insurgents vulnerable to targeted assassination or arrest prior to actual combat.