Untold millions have been spent by the West to combat HIV/AIDS with little result. Why has this disease been so difficult to defeat? One of the main reasons, Matthew Hanley and Jokin de Irala contend, is that most of the money has gone to the promotion of condoms and "safe sex." Very little has been directed to the fundamental cause of the crisis, namely, changing behavior. The effort to encourage abstinence until marriage, and fidelity within marriage, has been universally mocked by the media, the intelligentsia, and the political class, yet the success of this approach is undeniable. Hanley and de Irala show, through a careful review of the epidemiological evidence, that the most successful programs at reducing the incidence of AIDS have been in those African countries which have stressed the importance of limiting sexual contacts and remaining faithful in marriage.