Intense scientific work on HIV/AIDS has led to the development of effective combination drug therapies and there is hope that effective vaccines will soon be produced. However, the majority of people with HIV/AIDS in the world are not benefiting from such advances because of extreme poverty. This article focuses on the pandemic as a reflection of a complex trajectory of social and economic forces that create widening global disparities in wealth and health and concomitant ecological niches for the emergence of new infectious diseases. While the biomedical approach to HIV/AIDS is necessary, has prolonged the lives of many individuals and could offer much at the level of population health, it cannot, in isolation, improve the health of populations. To achieve the latter will require understanding and addressing the deeper social causes of pandemics. Broadening the discourse on ethics to include public health ethics and the ethics of international relations could contribute to reducing the impact of the pandemic and to preventing the emergence of new infectious diseases in the future.