The stakes in that question are becoming deadly serious. Of the 5 million people who contracted HIV last year, two-thirds lived in sub-Saharan Africa. In Swaziland, more than one-third of adults have the virus. In South Africa, nearly 30 percent of pregnant women are carrying it. Four years ago, an analysis of 38 studies by the U.S. Agency for International Development, mostly in Africa, concluded that circumcised men were less than half as likely as uncircumcised men to get HIV, apparently because of the susceptibility of foreskin. Last fall, reporting on a randomized controlled trial in South Africa, scientists found that circumcision reduced female-to-male transmission by 60 percent. "Male circumcision provides a degree of protection against acquiring HIV infection, equivalent to what a vaccine of high efficacy would have achieved," they wrote. It was, they observed, "the first experimental study demonstrating that surgery can be used to prevent an infectious disease."
Think about that: surgery as a vaccine. Drug researchers would kill for an HIV vaccine half as effective as circumcision. Condoms and abstinence often aren't effective because they require diligence. Circumcision works more reliably for the same reason foreskin enthusiasts hate it: It lasts forever. In the parlance of AIDS doctors, it's a "one-off intervention." Using the new data, scientists estimate that over the next 20 years, circumcision in sub-Saharan Africa could prevent 6 million infections and 3 million deaths.
What do you do when mutilation turns out to save lives? Anti-circumcisionists can't bear it. Years ago, they denied the HIV-prevention effect. When evidence from Africa defied them, they changed the subject to Europe. When evidence from Europe defied them, they changed the subject again. Some say a link between circumcision and HIV can never be proved. Others ignore it. Others insist it's unethical and false. It can't be true. It's heresy.
The strongest argument against circumcising babies to prevent HIV is that they're too young to consent, and they won't be at risk for the virus till they're grown. But we vaccinate babies all the time. Should we treat circumcision like a vaccine? At clinics across southern Africa, men are lining up, pleading, and nearly rioting to be circumcised. They want protection. Can we assume their sons would want the same thing?
Next weekend in Seattle, critics of genital mutilation are convening an international symposium on circumcision. The program lists 40 sessions. Not one mentions AIDS or male circumcision in Africa. Something's sorely missing from this conversation, and it ain't foreskin.
A version of this piece appears in the Washington Post Outlook section.