Through repetition, we're getting the soldiers used to what they do in the event of various forms of contact, whether it's an IED (improvised explosive device) or someone shooting at them, and then how they react to that.

As we gain new Soldiers, what these experienced veterans are doing is teaching them how to react under various conditions they encounter.

We try to make it as realistic as we can and then make it as challenging at the same time.

American soldiers don't do that. And we don't do it because we think it's fun. And we don't do it for our laughs. And we don't take pictures of it.

We're happy that they've all returned with no serious injuries. These soldiers are going to have up to 90 days to be left alone with their families. Then it's back to one weekend a month, two weekends in the summer.

[Burns says he has been particularly inspired by accounts of Japanese-American soldiers who left internment camps to serve in combat in Europe.] These men were only given one opportunity as volunteers and that was to go straight to combat, ... They went straight to the battlefield. It was very tragic. But they were some of the most amazing heroes of the war. And that's the kind of thing I didn't know when I started working on this project and the kind of thing I love to talk about. It gets me excited. And it's more fun when you can talk about it with people in a forum.