Items contained in a set container are considered const and cannot be modified. If they did, their identity might change but set wouldn't be aware of this, wreaking havoc on its internal structure as an item would be stored in a bucket where it didn't belong!
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.