NICHOLAS KRISTOF: But, in many ways, Judy, it's really the face of modern conflict.

It's what happens these days in civil wars that militias and warlords don't want to tangle with each other because they might actually get shot.

So, they turn their AK-47s on local women, and women's bodies become modern weapons of war.

And then, even when the conflict ends, the militias stop shooting other people, but this kind of rape, including of young children, continues. We have seen that in place after place after place.

JUDY WOODRUFF: But why—Nick, why are women the victims?

NICHOLAS KRISTOF: I think because people can get away with it, in a sense, because they don't fight back.

If you're a former of a militia and you still have your gun or you still have that kind of violent mentality, then if you set up a checkpoint on the highway and rob a truck, you will be caught and you will be executed.

And that's a priority for the government.

If you go around raping young girls, that's not a priority for the government and you don't get prosecuted and nothing happens.

JUDY WOODRUFF: Sheryl...

SHERYL WUDUNN, co-Author of "Half the Sky": But, at the same time, you terrorize a village.

JUDY WOODRUFF: That's right.

Sheryl, I was going to ask you about that and about, how widespread is this beyond Sierra Leone?

SHERYL WUDUNN: It's actually more widespread than anybody would like.

And it is a weapon of terrorism.

It is a way to actually make a statement that also terrorizes an entire community. Everybody has girls and women in their family. And so those people who are—whose women are afflicted are—are terrorized.

JUDY WOODRUFF: So, we're talking about across the developing world. Sheryl, why is it tolerated?

SHERYL WUDUNN: Well, I think that it's not so much tolerated as it is just—it's just people bear it.

They endure it, partly because there are no super-organizations, governments, large NGOs, other governments, who are stepping in to try and help or fix, remove the situation.

And I think it's an issue that people in general don't seem to care enough about to bring about change. And so if there is a way that we can say that everybody here in the world says that this is not something that should be tolerated, then I think people will take steps to eradicate it.

JUDY WOODRUFF: Well, Nick, in that connection, I think, in Sierra Leone, you talked to one investigator who had looked at, what, over 1,000 cases, but in all of those cases there was only one conviction? How can that be?

NICHOLAS KRISTOF: Well, because it simply is not a priority for the government.

And this is something that one can bring about change in. And, you know, we have seen it in Congo. We have see this in Sudan that, when there become penalties, then patterns change.

I mean, I—we have that in sex trafficking around the world, that if authorities go after pimps, then all of a sudden it becomes less lucrative, less attractive to be a pimp.

And so there are no magic bullets here, but one thing we can do is apply pressure to help raise this issue on the agenda. And if, instead of one-tenth of 1 percent of rapes being prosecuted in Sierra Leone, if it rises to 10 percent, that will send a powerful message through the community and it will lead to change.

I mean, one example, in the case of Sierra Leone, is it used to have the worst maternal mortality rate in the world. And then that got attention. Sierra Leone was embarrassed. And now delivery is free in Sierra Leone, and the maternal mortality rate has dropped by more than half.

SHERYL WUDUNN: It's also important to see that women can actually become part of the solution.

So if they can actually be empowered economically, then look at all that potential economic income that can be brought into a household.

JUDY WOODRUFF: And that's what I wanted to ask you about, Sheryl, because I think one of the focuses that you describe is turning oppression into opportunity. And I wanted to ask you, how do you do that?

SHERYL WUDUNN: There are many ways.

First of all, the government has to say it is very important for the populace to be educated.

So they need to mandate education for everybody, including girls. And then they have to say, well, it's also that we allow our women to work in the workplace, to actually become productive members of society.

And once you give a woman education and a chance to work, she can astound you.

JUDY WOODRUFF: Sheryl, I want to ask both of you, for people who are sitting at home watching this on their television or their computer, what can they do about this?

NICHOLAS KRISTOF: We have website, halftheskymovement.org. And we have an action tab there.

So our hope is that people are going to watch the documentary on PBS, and then they're going to go to that halftheskymovement.org website and then they're going to do something. And it may be make a donation or engage with some organization or volunteer their time or write a letter.

But, I mean, the ultimate metric of success for this documentary isn't the number of people watching it. It's the number of people who then take action and get involved.

SHERYL WUDUNN: Even spreading the word is really important, because the more people who see that this is an issue, the more people who begin to care about this as an issue.

Then, the governments start to realize that this is something that voters care about. And they will actually vote for policy changes, which is also very, very important.

JUDY WOODRUFF: Yes, I wanted to ask you all about this, because, you know, in many ways people look at these scenes. And while it certainly tears at your heartstrings, you think it's so far away, am I really connected to this?

NICHOLAS KRISTOF: I mean, I guess there are a couple of answers to that.

One is that there are real needs we need to address right here at moment. And, sure, sex trafficking is worse in India or Cambodia than it is in New York or Washington.

But we have problems here. And if we want to have the moral authority to tell other countries to clean up their act, we have to do more right here at home.

But the other thing is that I don't think—there's one view that we really need to solve our problems at home before we begin to address problems abroad.

And I think the policy there is first that interventions abroad often get more bang for the buck than those here, that it is very cheap to save a life abroad, and, second, that our compassion and our empathy shouldn't depend on the color of somebody's skin or the color of their passport.

JUDY WOODRUFF: Sheryl, do you want to add anything to that about why people should feel connected to this?

SHERYL WUDUNN: Well, I also think that there are many things that we can learn, not only from policies and programs that we have implemented here at home, but also abroad.

There's a lot of learning that we actually are garnering from programs that have been established abroad to attract—to address trafficking, because it is a problem that started abroad, that was much more of an issue abroad before it came to our own shores. So, they have had a longer history.

Also, in a place like Sweden, there is great deal of learning in the way they have actually tried to eradicate trafficking. They have been much more successful than other societies in focusing on demand, on the johns. And we can learn from them as well.

So, I really think it is a globalized world. We need to actually look at this as a global problem.

JUDY WOODRUFF: Well, we thank you both for helping us understand more about it. Sheryl WuDunn, Nick Kristof, we thank you both.

SHERYL WUDUNN: Thanks very much.

NICHOLAS KRISTOF: Thanks so much, Judy.

"Half the Sky" airs on most PBS stations tonight and tomorrow night. You can watch more excerpts about Sierra Leone, about India's caste system and education in Afghanistan on our website.