Yes, living in the USA it is a more properous Country then most others, but we do have our own problems and cash shortages to solve all of them. But with other Countries being even poorer the resources would go to solve their problems first as everyone here eats. As far as the nationalistic identity I don't think it really matters.
If all people were one nationality there would be some other reason to have a war over. Then there is the question of what type of Government would this one Country have and who would run it. Would it be Democratic or Parliamentry or some new form?
What would happen to the developed wealth that has been accumulated and many other financial factors for the markets.
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.