Countering the familiar peace narrative, it became increasingly common during the 1990s to question liberal war-making efforts. This led to the resurgence in “just war” theory, as the desire to save strangers became an increasingly violent pursuit. Although it has since been argued that the exceptional politics aligned with the U.S. war on terror has put this notion of humanitarian war into crisis, this essay argues for a more nuanced reading that moves beyond limited sovereign frames of reference. Not only has the history of the liberal encounter been marked by violence in a manner in which notions of right appear highly contingent, but aligned specifically to life-centric notions of progress, the biopolitical contours of liberal war show a remarkable capacity for adaptation, change, and innovation. Although liberal war therefore conditions the very possibility for liberal rule, it reveals a number of key principles that set it apart from conventional state-centric frames of reference. This essay maps out the ten key principles in order to gain purchase on twenty-first-century biopolitical warfare.