Across African countries, prevention policies are unrelated to the prevalence of HIV/AIDS and, even in countries in which they were successful, these policies are often unstable or reversed. To explain these two puzzles, we propose a simple political economy model that examines how prevention policies and the epidemic dynamics are jointly determined. Prevention campaigns affect both citizens'behavior and their perception of the role of public policies in fighting AIDS. The behavioral changes induced by the policy, in turn, reduce the risk of infection for sexually active agents, and this creates political support for future policies. The two-way relationship between prevention policy and awareness generates two stable steady-state equilibria: high awareness/slow prevalence and low awareness/high prevalence. The low prevalence equilibrium is fragile: the economy can easily drift away towards the high prevalence rates as they also imply less active prevention policies. We then conduct an empirical analysis of the determinants of public support for HIV/AIDS policies using the 2005 Afrobarometer data. High prevalence rates translate into public support for prevention policies only in countries which carried out active prevention campaigns in the past. The proposed framework extends naturally to a large class of public health policies under which awareness partly follows from the policies themselves.