No cause there is no use for them There's plenty of use for them--most planes have window wipers--but a fighter jet doesn't have them because the wind would tear them off, and because the wiper couldn't go around the curve on the canopy. The canopies have a coating that repels water, like RainX does for cars.
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.