I begin by introducing some traditional interpretations of the non-combatant immunity principle. I discuss the failures of the immunity principle to protect civilians from the effects of 21st century warfare. I then introduce the argument that the increasing technological sophistication of the weapons of war could save the immunity principle, but show that the promise of technology is a false one. I criticize the conceptual foundations of the immunity principle. I discuss the paradox of “the principle of double effect” and the doubt that it casts on the viability of just war theorizing more generally. I then introduce a principle that I argue can solve the contradictions within the immunity principle specifically and just war theories more generally: empathetic war-fighting. Empathetic war-fighting, derived from feminist just war theorizing, focuses on responsibility and people’s security, particularly at the margins of global politics. I conclude by discussing the possibilities for a new immunity principle based on empathetic war-fighting.