Escalation is commonly understood as the constant aggravation of mutual sanctions between two conflicting parties. While escalations have been intensively explored within the empirical sciences, philosophy and ethics have scarcely touched upon the issue up to now. This paper tries to fill this gap by analysing the normative structure that underlies escalations and determines their psychosocial dynamics. The experience of injustice suffered by the opponent and a resulting desire to perform unjust acts of one's own are highlighted as the essential ingredients of escalations. Against this background, the remarkable stability of escalating conflicts as well as certain paradoxical phenomena in escalating behaviour can both be satisfactorily reconstructed. Additionally, familiar aspects in the realisation of escalations can be better understood and new options for terminating escalations may be developed.