Thanks for the thoughtful response! I do have to disagree with your claim of selection bias. Randomized, controlled trials should help to deal with this (though unfortunately you can't do blinded trials in this context.)

The biggest issue with circumcision seem to be that, over a lifetime, the 50-65% protection from HIV doesn't mean that much. Give it a few years and that can pretty rapidly fall to an insignificant level. Whereas condoms, used properly and every single time (a high hurdle to mount), probably have a protective effect closer to 90%. That's a lot better than circumcision.

The next big issue (probably the real big one in this context) is risk compensation. It does not seem that unlikely that men who would have otherwise used condoms think that getting circumcised will protect them from HIV, and stop using condoms as a consequence.

That's incredibly unfortunate, because condoms are not perfect (poor adherence limits their effectiveness to around 70% in the clinical trials I've seen), men frequently fail to use them, and the combination of condom and circumcision is much better than condoms alone.

It's a pity men receiving circumcision aren't receiving appropriate counseling, since that is a cheap and effective intervention that would have a huge impact, especially combined with circumcision. If you reduce the risk men face when given condoms by 50-65%, that's a huge difference.

By the way, I'm a little skeptical about some claims of risk compensation. I personally take HIV PrEP, pre-exposure prophylaxis, which is 100% effective at HIV prevention with proper adherence. Studies have shown that there is no risk compensation in people on PrEP (people put on Truvada don't get more STIs than people who don't take it!). I realize these findings may not extend to African populations, but I sure wish that disinformation and risk compensation wouldn't be so prevalent there.