Well of course that all depends on what was written before the written text you have here. "As we humans grow old and nature grows new" in itself is not a simile, because there is a missing part to that, which would be the ending, if this were a sentence. You would have to say something like, "As we humans grow old and nature grows new, life is continuing as the grass stays green and the sky stays blue."
Even though the word "As" is used here, you aren't exactly comparing a human growing older and nature growing new *with* the word as such as so: "Nature growing new is *as* humans growing older, always changing and leaving with the wind." So, no, "as we humans grow old and nature grows new" is not a simile.
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.