Just to reiterate a comment that I made in an earlier post—the Taliban's rise to political prominence in Kandahar occurred precisely because they clamped down against child sexual abuse (as well as a number of other acts that were widely considered immoral). While I don't doubt that the (male) child sex trade flourishes, I wouldn't presume that it has widespread local support.

It is a cultural thing that will take years to change -- if it is ever changed. We have the same sorts of problems here in the west, we're just more discreet abou it -- or more PC and won't condemn it, one or the other.
As is this, but I'm noticing a white-hot rage on this one compared to what I encounter on the abuse issue. Have to agree, though, on the "we're not there to impose our culture" - too many historic examples from all sorts of other cultures trying the same thing to be optimistic about the results of such an exercise.
The real key to addressing this is to determine—not assume—how the locals would react to actions taken to limit such abuses. At the moment, our real information level on that seems to hovering close to zero.