Apparently he was "ashamed to be an American" according to emails he sent to his parents prior to his "capture."
Was he "captured" or did he desert (and was then captured?)
Robert Bergdahl’s twitter page gives some very interesting insight into the family. He seems to be awfully sympathetic to muslims too and blames Nigerian aggression for Boko Haram among other things.
https://twitter.com/bobbergdahl