As the nature of armed conflict continues to change, so the living ethical tradition<br />that is just war theory has to adapt to meet new challenges. This paper offers a<br />proposal for extending just war theory by incorporating into its framework a human<br />capabilities-based ethic drawn from the work of Martha Nussbaum. This new<br />approach is analysed in the light of two important recent challenges to just war<br />theory: David Rodin’s critique of the principle of national defence, and the emerging<br />doctrine of humanitarian intervention. While the results of this analysis can only be<br />considered to be preliminary, the authors argue that indications are that<br />supplementing just war theory with Nussbaum’s human capabilities-based ethic, or<br />something similar, could yield significant benefits for the ethical analysis of<br />contemporary armed conflicts.