Chiming in as another child of a Vietnam Vet. My father never recovered from his time there. He fell in love with the food, the languages, and admittedly the women (He thought Vietnamese and Thai women are the most beautiful in the world). As a history major, I was always fascinated by the time, and he would never talk to me about it.
He developed a medical condition while over there, that never went away. He had nightmares. He lost friends.
So while it is a fascinating time, it's not really a 'game' friendly theme, I don't think.