There is actually a Mahalo How to on the subject: How to Write a Thesis Statement. Since I wrote it, I will refer you to it. If you have any questions, feel free to either comment here or send me a direct question.
Writing a thesis is challenging, but if you follow the guidelines you will be able to write an effective one. Choose a subject that you are familiar with. You can find more information here: ldeo.columbia.edu/~martins/sen_sem/thesi....
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.