Those women (and two men, I think) were friends and co-workers of some friends of mine who were also in Afghanistan at that time. They LOVE the people of Afghanistan and gave up the comfortable lifestyle here because they wanted to help the Afghani people. I heard Dayna and Heather speak a few months after they returned home, and their lives were profoundly touched by the street orphans they helped feed, and the women who came to their house to visit and to receive supplies. Their first priority was to show compassion on the poor, needy, and homeless. They did not prosyletize, and they were very careful to show respect toward the religion of those they were serving.
They were set up by the Taliban. One young man, who was manipulated by the Taliban officials, asked them to talk about Jesus and show the Jesus Film. A person from a different NGO happened to have the film on CD in the Pushtin language and gave them the copy. The man reported back to the Taliban after he saw the CD and that's when they were arrested. I'm not saying that they did not want to talk about their faith, but they weren't pushing it at people. They waited until they were asked, which seems fair. And even if they'd never been asked, they would have continued serving and helping the people.
You can't judge one group of people by the actions of another. I have nothing but respect for people who are willing to give up their privileged existence to live in a foreign, hostile country that is one of the poorest in the world, and that treated women like property. They risked their lives because they believe that Jesus taught that we should care for the poor, the widows, and the orphans. They lived out their beliefs, even when it looked like they might die because of it. When you have gone and done as they did, when you understand the situation like they do, then maybe you have the right to pass judgement on their actions. Until then, I would respectfully suggest that it would be better to not be so quick to speak.
I would encourage you to read their story. You can look at it on Amazon at this link:
http://www.amazon.com/gp/reader/0385507836/ref=sib_dp_pt/102-3860497-1387309#reader-link