It's difficult to give a specific answer because the U.S. Has become a home to almost every nationality. However, civil war/unrest in a country and poverty are two of the main reasons people immigrate to other countries. There are cases where government or military personnel seek political asylum to avoid imprisonment or execution in their home country.
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.