Never before has it been clearer what interventions must be implemented to mitigate the adverse health consequences of wars and natural disasters, and what standards those interventions must strive to achieve; similarly, the range of interventions at our disposal has never been greater. Despite these advances, reviews of the global relief system suggest an ongoing failure to deliver. They also highlight the dire lack of credible data to help us understand just how much populations in crisis suffer, and to what extent relief operations are able to relieve that suffering. Political considerations often obstruct the delivery of appropriate relief. The premise of this paper, however, is that lack of knowledge is also an important limiting factor. This paper argues the need for advocacy for timely and appropriate relief, grounded in clearly outlined, scientifically sound reasoning, focusing discussion on substantive matters and reducing the scope for political manipulation. As such, the paper aims to enable readers to better face up to the political and bureaucratic aspects of the global relief system.