Abstract
Defence cases with an escalatory structure, in which the levels of violence between aggressor and defender start out as minor and then become major, even lethal, raise sharp problems for defence theory, and for our understanding of the conditions of defence: proportionality, necessity, and imminence. It is argued here that defenders are not morally required to withdraw from participation in these cases, and that defensive escalations do not offend against any of the conditions of defence, on an adequate understanding of them. No plausible interpretation of proportionality or necessity excludes defensive permissions in escalatory cases. Moreover, the structure of escalatory defensive cases also sheds useful light on permissible responses to conditional deadly threats. This is because we can analyse conditional deadly threats as disguised cases of escalation. Because defensive resistance is permissible in escalatory cases, it is also permissible in cases involving conditional deadly threats.