Because God wanted to test the humans and it wouldnt have been possible without satan coming into picture so satan was destined to rebel...it's God's mystery, but only the spirits would be punished evil spirits and not the souls, probably God will raise the curtain over this secret on the Judgement day that He will separate existances from spirits and bad spirits will go to hell forever, but not the existances or souls if they had faith and asked for the forgiveness....God's merciful He will forgive the existances... more.
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.