UINavigationController is a stack of view controllers. Every view controller has a property called as navigationController which represents the UINavigationController to which it belongs. Thus, if a view controller doesn't belong to a UINavigationController (in other words, if a view controller is not present in a stack), it's navigationController property would be nil.
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.