The U.S. military is using virtual worlds to help treat veterans suffering from post-traumatic stress disorder (PTSD).Soldiers suffering from PTSD wear goggles and hold weapons in the presence of a clinical psychologist and discuss their reactions to situations they experience in a virtual reality designed specifically for their cases.

You can watch this footage on PBS FRONTLINE's Digital Nation Web site, which is uploading content as material comes in for a documentary to be aired later this year. Rachel Dretzin, the program's director, told me that the idea of the Web site is to include more than a film could show in an hour-long slot. "On the Web, if it's interesting, it can have a life," she said.

Digital Nation will post eight to ten different Web episodes in the run-up to the broadcast of the Digital Nation film; the Web site includes blogs from Dretzin and other members of her team, and Dretzin hopes that interview subjects and visitors to the site will contribute ideas and even content. A section of the site features user-generated content. The motivation for the entire project is to open a dialog about the increasing pace of digitization of modern life. "The dominant emotion people feel about digital nation is anxiety... We're trying to create a space where people can engage about it directly," she said.

The current "Digital Warriors" episode shows how the military is making use of technology to help soldiers train for combat, fly unmanned bombers into enemy territory and even have a conversation with a fully interactive virtual soldier. Many of the technologies, created by the Institute for Creative Technologies, can also have civilian applications. The same technology used to create the virtual soldier can be used to help social workers interview patients or to teach business school students negotiating skills.

The military also uses technology, like video game controllers adapted to fly the drones, created for commercial purposes.

One of the subjects of the episode is P.W. Singer, author of "Wired for War," who notes that technology is changing the very nature of war. For example, because the drone pilots can fly aircraft into the Iraqi desert from their base in Nevada and then drive home for dinner with their kids, "the old definition of 'going to war' has changed in our lifetime,' he said.

The benefits of being able to fight wars without putting our soldiers at risk has obvious advantages, but it also means we could be more likely to go to war without thinking through all the ethical and pragmatic long-term consequences. Putting that on the table is an important part of Dretzin's mission.