In defence of necessity

This paper disputes Uwe Steinhoff’s view that a jus ad bellum requirement of necessity can be merged with a condition of proportionality. It argues that the proposed merger detracts from a conceptual and moral understanding of the structure and rationale of both the necessity and the proportionality considerations applicable in a range of moral contexts, including those of war and so-called lesser evils cases, where these conditions are intended as action-guiding.