Your question needs a lot more detail. But if all you want to to show an 'exception window' and allow the user to do anything else only after she dismisses this window, I think all you need is a MessageDialog: See JOptionPane.
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.