The humanitarian principles – humanity, neutrality, impartiality and independence – have come to characterize effective humanitarian action, particularly in situations of armed conflict, and have provided a framework for the broader humanitarian system. Modern counterterrorism responses are posing significant challenges to these principles and the feasibility of conducting principled humanitarian assistance and protection activities. This article explores the origins of the principles, the history behind their development, and their contemporary contribution to humanitarian action. The article then discusses some of the ways in which the principles are threatened, both by practice and by law, in the Australian context, and finally makes suggestions as to how the principles can be reclaimed and protected for the future of effective, impartial humanitarian action.