A Detached entity is an entity that has an identifier, but is not present in the current session. When you try to save it, hibernate complains. You have to put it back in the session.
This is done via entityManager. Merge(..) .
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.