Many coming back from War have a hard time talking about it, even with their kids.... In the best of circumstances. Many also suffer from things like ShellShock/PTSD (samething), which they can either take out on thier kids or not deal with them for fear of taking it out on their kids. My family has a lot of millitary in it, I have seen this personally. Handle it however you see fit but just be aware you may be picking at an old wound that even your father does not understand about his father.