Is it ethical to study what ought not to happen?

In the Democratic Republic of Congo, only an estimated 2% of all AIDS patients have access to treatment. As AIDS treatment access is scaled-up in the coming years, difficult rationing decisions will have to be made concerning who will come to gain access to this scarce medical resource. This article focuses on the position, expressed by representatives of Médecins sans Frontières (MSF), that the practice of AIDS treatment access rationing is fundamentally unethical because it conflicts with the ideal of universal treatment access and the human right to health. The conclusion is that MSF's position lacks coherence, has negative practical implications, and is unfair to governments struggling to increase patient's access to AIDS treatment in unfavorable circumstances.